Father, Forgive Them; For They Know Not What They Are Doing

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When I wrote American Whiskey by the Numbers I had never before actually looked at Bourbon, though I’ve certainly drank my fair share. Believe it or not, I haven’t read any of the recent titles on the subject and I don’t really know what anyone else knows. Are all the mash bills, fermentation, and distillation parameters known, or am I blowing the lid open on a big story? It is slow going finding out and I probably got the lowest amount of interest ever in a story I thought was pretty significant. Be warned, this saga is a bit of a disillusioning mess.

Since profiling the document, I’ve read two older books on Bourbon plus a few great old research papers. Some really interesting things turned up and I’m basically convinced that Maker’s Mark saved Bourbon from destroying itself. I’ll get to that slowly. I used to think that the American whiskey story lacked the wide dimensions of other traditions, but boy is that wrong. It is full of churning culture wars that pushed it to the brink and they are still unfolding.

The first book I read was by Sam K. Cecil who’s big claim to fame was being the scientist counterpart to practical distiller Bill Samuels at Maker’s Mark. It was sort of a dead end, believe it or not. The book turns out to be a lot of births and deaths and locations which does interest a lot of people, but does not help our quest.

Even though Cecil was in the thick of it, his writing does not explain the document. I was hoping for someone as crazy as Fitzcaraldo grappling with beauty. I’m always looking for aesthetic opinions, style, and other criteria by which to judge what is fine, what is commodity, and what is flawed (regrets and missed opportunities).

Cecil, however, was kind enough to point me in the direction of Harry Harrison Kroll’s Bluegrass, Belles, and Bourbon (1967) which is chock full of confrontation with the 20th century and modernity told through the guise of a book on Bourbon. It is also told by a guy traveling around with a nun, sister Kathy, as a chaperone. Initially, I imagined it kind of like Two Mules for Sister Sara, but there never were any plot twists.

Before I complement Kroll, I need to lay down a few asterisks ∗† and luckily we all just received some excellent guidance in recognizing these matters from Wayne Curtis. Because the book isn’t solely a compendium of births, deaths & locations, and it encompasses all that grappling and confrontation, Kroll reveals himself to probably be a misogynist and a racist. He says uncomfortable crazy uncle things constantly. The writing style is unusually candid which provides evidence for my diagnosis. By the end however, when the book appeared to be about much more than Bourbon, I was getting the sense that his was a flexible mind. Kroll overcame prohibitionist ideologies, and I began to suspect that unlike David Embury, Kroll was not likely to die a racist. Sadly, I don’t think he was going to make much progress with his casual misogyny (Kroll actually died in 1967 so technically I’m very wrong).

You can really time travel in this country, back then and even now. I see a lot of it in the restaurant. Many people have hairstyles like they haven’t left the house in 15+ years. In that time they just did not absorb anything that influenced the style they present themselves with. You hear economic and political conversations that are 15 years dated like someone heard something so formative that they never read the news after. Eight years in and seven years to go, countless people will still be talking about her emails.

Kroll does a lot of that fifteen year time traveling, or he sort of watches himself doing it when he writes later. No wonder he must travel with a guide. He is constantly pursuing the effects of prohibition & repeal thirty years prior to his trip, revealing that for some people it wasn’t that distant. This can strike today’s reader as odd. The book becomes comparable to Infinite Jest with some readers being bored to tears by the parts on tennis and AA, but I actually enjoyed them the most.

A large part of the book, where the bluegrass and belles come in, is Kroll romanticizing his own typical American past where he grew up barefoot, eating squirrels, walking to school uphill both ways, and apparently had a very formative early job making barrel staves at subsistence pay. He keeps aligning himself with a young Abe Lincoln that did grunt work under his father at Watty Boone’s distillery. Kroll warms up that story a few times almost coming across as a senile repeater until he finally tells it, and tells the best version of it I’ve ever heard. He is either slightly nuts or pretty damn masterful in his gonzo ability to romanticize, humanize, build myth, and plain old story tell. He is a lot of Bourbon personified.

Eventually Kroll time travels from all this back into the bottling room of the day at Heaven Hill where teams of women are earning great middle class wages, the industry is proud of paying, and gives a “ya don’t say?”, like it all snuck up on him. Things are always sneaking up on Bourbon. The recent Bulleit story is no surprise. You don’t really know what the time traveler thinks about it. Was he happy American prosperity was spreading and women could be independent or did it threaten his masculinity and cheapen the hard years of splitting barrel staves he romanticizes? The time traveler walks an unclear line, but it has the effect of humanizing the industry.

The Shapiras snuck up on Kroll and he may have brought some antisemitic baggage to their “temple of iniquity” though it is never as pointed as his other major short comings. These furriners were an assault on his brand of Kentucky negative nationalism and they were getting rich. Hiring a Beam as master distiller didn’t make it right. Kroll keeps noting that he can barely taste the difference between bourbons so its all in what they represent to him. This experience was disillusioning.

Before I move on a little, I will quickly note that a possible reason we don’t see more information turning up about New England rum production pre prohibition may have been the influence of the temperance movement and the semantics of demon rum. Kroll, noting about doing his research, clues us into a pacing of the temperance movement I wasn’t really aware of. The peak of New England rum as modernized by Dr. Harris Eastman Sawyer unfortunately coincides with that tenuous time when it wasn’t wise to publish much about industrial demon rum. The right to a drink was hanging by a thread for quite a while before it was actually cut.

Our time traveler sets us up to see Bourbon’s confrontation with modernity. Practical distillers had to start competing with scientists (even though they had somewhat different objectives). The most practical of distillers had to compete with other practicals who were going huge and creating very large operations.

We don’t really recognize the practical distiller today yet they are blooming all around us. Kroll likes to celebrate them and believes they may be solely capable of making an uncompromising fine product even though so few then actually drank it (I never fully appreciated that last detail). Today many hold practicals with a mild disdain.

To be practical in this context means you have no formal education, and back in the early days, many were even illiterate. They never took a chemistry or biology class and operated from an old fashioned notion of empiricism and a heightened intuition. Practicals were viewed as born with it which kept the profession dynastic, male and mostly white (though there are some awesome stories of black distillers in America and Kroll notes a few). Practical can be authentic, but that is another term we haven’t given much thought.

Today, all the new American distillers are practical distillers with very few exceptions (and the acceptance of consultants). They’ve started their businesses with grit and determination plus probably only two PDFs and a skimming of this here blog. Start up costs are so high that they also often have generational wealth, IPO money, or predatory capital that will eventually rob the best. They compete with huge well researched scientific operations who have also monopolized distribution channels. The practicals still all sound all very American, but somehow the consolidated establishment, big Bourbon, has really won the public over.

The scientific distillers of Kroll’s era were the Seagrams, Hiram Walkers and their Herman Willkies and Paul Kolachovs which were all commodity producers. Commodity spirits aren’t exactly authentic, but authentic working people often only drink commodity liquor. See why I’m avoiding the authentic concept?

In a great chapter, Kroll singles out a wonderful new fusion of the two which was the team of Bill Samuels and Sam Cecil (he returns to this story!) working to build Maker’s Mark which to me seems like it saved Bourbon. When Kroll visited in roughly 1967, Maker’s was only producing 20 barrels a day relative to other operations that were up to multiple hundreds of barrels a day. Many of today’s craft operations are starting at one barrel per day.

Bill Samuels kicked off a new era of fine whiskey using a frame work I call guided traditional practices. The stylistic ideas of practical distiller Bill Samuels were proven scientifically and made to scale forward and up by lab guy Sam Cecil. Flavor returns as modus operandi, not price and volume.

Around this very same time, wine was going through the same paradigm shift led by Grigch Hills and Stags Leap plus the others that won the Judgement of Paris. Wine did however move in the opposite direction. Samuels got himself a lab while in wine, the lab guys like Mike Grgich got practical and embraced flavorful risk in ways not seen in the commodity framework. Wine in America, many don’t realize, started as a commodity product because it initially was a salvage product. The priority was table grapes, then raisins, and lastly wine, which was for a long time a skid row beverage. Walt Whitman probably didn’t drink American fine wine and there are no tales tying wine to great generals like there are of Old Crow.

It is really important to understand these tensions and transitions so we can understand other spirits categories. You could be a practical distiller in the Bourbon racket using yogurt technology (I say that because that is basically how advanced it got) and get pretty far, but could you do it with rum? Can you do it with grape brandies like Cognac?

Jamaica rum, as we revere it, was success at random until the top Victorian scientists stepped in. These guys were following the development of modern chemistry and yeast technology by the day. Cognac is the most quality focused spirit out there because it has it’s back up against a wall. Every acre of the appellation is pretty much planted so they cannot expand, they can only improve. Cognac has easily moved beyond the merely practical or scientific to the complete state of guided traditional practices. Tequila is just entering the end of its commodity phase. Consultants have gone in, homogenized everything with pure yeast cultures and efficient processes, stripped all individuality and beaten the price into the commodity floor. A few productions are finally starting to investigate the flavor they left behind and revive it with more than marketing speak.

Before we move on, I should quickly state my theory that the scientific era probably allowed women and minorities into white male dominated production positions. If you could handle the lab work, you could handle the job and all the white male mysticism was no longer relevant. Seagrams early on, employed some notable female chemists.

Kroll gives us some great insights into the document. He visits Yellowstone noting their huge operation and their production angle of mellow mashing to make a light whiskey distilled in a giant column and he implies the removal of fusel oil. If you remember, this was the controversial technique and avenue for loss of identity that provoked the IRS survey of whiskeys that is the document. Am I grasping here or is that umbrella-like do-dad not a fusel oil separator?

No itemized list is presented, but we also get the sense that there were far more distilleries in operation than what the IRS selected for their survey. Very interesting to note is that the exclusively sweet mash producers like distillery no. 2 and no. 42 likely weren’t tiny little heritage operations. Their sweet mash did make inferior whiskey according to Kroll (and production theory) and he sadly doesn’t even bother to name names, but he does note that they were in Daviess county. There is a bit of ambiguity to the logic of his paragraph, but he may imply that some sweet mashers were among the largest in the state.

Towards the end, Kroll goes to visit the Medleys and gives us the greatest hint behind the M&A churning that has always been a hallmark of the industry. Taxes were everything. Distillers would build up value in the business then unleash it all at once in a sale instead of taking it steadily year by year. Capital gains taxes were very different than income taxes and I don’t think it was proper to have private jets and write off your golf outings like we do today. Corporate decadence came in the 1970’s from Barbarians at the Gates culture. That is what consumed Tribuno vermouth, remember?

Who knows how long that tax logic was true, but it makes a lot of sense to these highly rational thinkers who didn’t even drink the stuff they made. Foreign money would come in and the labels would get traded around. The foreign money would have to pay the dynasties of practical distillers again to operate the places. It was a little bit of a racket.

These practical distillers often said dumb patriarchal shit like he could never make whiskey as great as his father (and on up the line), but none of these people ever really cared that labels were getting swapped and not corresponding to their juice. Bill Samuels may or may not have carried a family yeast, but he did use Stitzel-Weller as a template, mash bill and all.

Beauty, that thing we’ve been trying to confront, has always been a little lopsided in American whiskey. Beauty is the composite of extraordinary sensoriality and exemplary human behavior. Here its git-up-and-git over the specifics of grist. Grain bills don’t matter, If you’re allowed to pick one thing, they pick yeast because it is the easiest to mystify. We’re supposed to admire hard work and tradition with a lineage that leads us through Lincoln to pastors like Elijah Craig.

If you pursue that other side of beauty, that aesthetic sensory side, which with distillation takes startling science, you’re headed down a road to decadence and demoralization. Stick the Venus of Willendorf in the bottle and you’ll just get alcoholism and depravity. Did we learn nothing from the temperance movement? Teams of conspiring scientists, corporatism, undermine the individuality of the loan practical man. Bourbon is just fraught with moral peril. Who’s side are you on?

No doubt clutching his copy of Huysman’s Against Nature, Hiram Walker’s own C.S. Boruff writes a plotless listicle of actionable aesethtic advancements for the journal of Industrial and Engineering Chemistry in 1937.

Repeal of prohibition ushered in an important new phase of the business of manufacturing whisky. Chemistry, biology, and engineering meant little or nothing to the old industry, occupied as it was with its deep obeisances to age and hoary tradition. To the reborn industry, science and technology have become essential tools.

Who you callin’ hoary?!

Age was the fetish of the distillers and of the drinkers of alcoholic beverage of two decades ago and with many it still occupies a sacred niche. Even the niche has vanished before the enlightening discovery of research which form the basis of today’s distilling practice.

You’re going to let him talk about your Pappy that way!?

Necessarily there are three steps in the manufacture of beverage alcohol: fermentation, distillation, and maturing. For many reasons which will become apparent, the ancient practice of distillers place particular emphasis on maturing over long period of time and the fetish of age became the idol of the industry.

This guy is quite confrontational.

The crude distillate of old-fashioned stills was harsh and unpleasant and long aging in charred oak barrels was known to accomplish a remarkable change in it. After long maturing, whisky lost its rough harshness, acquired a pleasing aroma, and delighted the palate. Chemists explained this as the removal of certain unwanted constituents and the chemical rearrangement of others to yield a palatable result.

So the practical distillers produced ends to justify their means, but this guy gives credit to the chemists. The ends didn’t matter if you didn’t understand them. It is an assault on intuition that would build throughout the rest of the 20th century.

Either this fact failed to reach distillers or they were too busy with other matters to heed it. In any case, it remained for the reborn whisky industry to apply this fact to its operations to the advantage of all.

“What we need is a bigger ideology”

The new technic is exemplified in the operation of Hiram Walker & Sons, in a plant at Peoria, Ill.

No one ever calls it Hiram Walker & Sons!

In the old practice of the distillery, fermentation was allowed to take place as it would in open wooden tanks which were never sterilized and into which every possible wild yeast was encouraged to come and grow.

This is an assault on yogurt technology! And a criticism of the IRS!

Distillation was conducted for the prime purpose of recovering every bit of alcohol possible from the mash without regard to other constituents. The result was a distillate which contained all the volatile (with steam) constituents found in the fermented mash and whose maturing required long stretches of time to correct its deficiencies.

Dr. Science here thinks he’s superior to a practical distiller. But, we just learned from Kroll that they built up value in their distilleries via inventories then unleashed it all at once in a sale. Practicals were no fools and they dangled the promise of the buyer extracting value by walking down the aging times. Clever like a fox! Problem is, its a routine you can only use for so long before it is worn out and Kroll was wading through the late years and a talking to a cast of characters like Marcella McKenna who had already played that hand.

The vital importance of the maturing process justified analysis and investigation, and from this came the key to the whole situation. Maturing was found to consist of two parts. (1) corrective aging and (2) maturing. During the corrective aging period the objectionable flavor and bouquet-producing substances found especially in whiskies made by the “rule of thumb” method, are absorbed and modified through assimilation, while during the second stage (maturing) slow chemical reactions occur between the congeners (nonethanol constituents) of the distillate and the wood extractives, whereby the desired bouquet is attained.

Rafael Arroyo, writing at the same time on rum never talked down to anybody like this. Boruff goes on and starts to walk the reader through procedures like yeasting. Yeast has been that one thing that practical distillers had really latched onto to build myth and create exclusivity, but they never did perform any analysis that could prove that their chosen organism hit objectives better than another. Boruff doesn’t tackle this issue, but mainly claims that all practical distiller’s ferments were tainted by aroma-negative wild yeasts.

The concept of whiskey of two decades ago reached the point of making the product an alcoholic solution of a quantity of congeners—that is, compounds other than ethanol present in whisky. In other words, the congeners themselves became the prime objective of the distillery and the alcohol merely a convenient carrier for these flavors. On this basis long maturing to permit the completion of slow chemical reactions in the distillate and the dissolving of extractives from the oak barrels containing the spirits was essential. The new industry, however, has been built upon the concept that the primary objective is the alcohol in the finished whisky and that such congeners as are present make this potable. The difference between these two conceptions has enabled the new industry of whisky distilling to provide whiskies of high potability and palatability, and yet whiskies which may possess quite different characteristics from these of even a quarter century ago.

Wow. Did Kroll ever have any sit downs like that? Sister Katherine would have started murmuring over and over, “Father, forgive them; for they know not what they are doing.” That is where tequila is at right now, but we do know that if we pray hard enough, the next phase will be guided traditional processes, and be delicious.

In the old art, the fermentation was conducted and the choice made of the raw materials used in it to foster the formation in the ultimate distillate of alcohols, aldehydes, and acids in variety and abundance. This end was accomplished by encouraging the growth in the mash of organisms other than the yeast. When the product of a fermentation of this kind was distilled, the distillate was an extremely unpalatable product, requiring extensive subsequent correction to give it the desired bouquet and flavor. The larger the proportion of congeneric substances, the longer the period of aging required and the greater the quantity of extractives needed to balance their effect.

Boruff is describing a large aesthetic shift and it doesn’t start with consumer demand for lighter whiskeys which is the narrative we’ve been peddled. These guys were simply condescending the work of the practicals and chalking up the old sensory experience to randomness, accident, and byproduct (but not the regrets and missed opportunities that are flaws). They also had to extract value from brands they paid huge prices for. A departure of style was needed to justify themselves.

In contrast to this, the new whisky industry has devoted its efforts to finding methods of fermentation and distillation which control the original formation of congeners in the mash and which subject those present to logical treatment. Smaller proportions of congeners are balanced in the finished whisky by smaller amounts of extractive matter, and at the same time, since extent of the chemical reaction involved is materially reduced, the time required for them to occur is much shortened.

What is cool about this is that these guys were in some ways neck and neck with Arroyo and rum. At the same time, they were moving in opposite directions. I’ll leave that for another time.

In other words, by making distillates containing predetermined amounts of congeners, the subsequent treatment to make the alcohol palatable is predetermined.

They didn’t quite make good on this inevitability engine, but they kicked off the pursuit. Currently it is at work in the industry using startling amounts of inline monitoring and data science. How else could you manage scarce resources and scale products to global demand?

In the selection of the grain the primary consideration is its starch content, since other constituents (proteins, etc.) are always present in ample amounts. In the old days, distillers apparently failed to recognize that differences exist between the starch content of various grades of grain and consequently always bought the cheapest. The fallacy in this has been amply demonstrated and the first and second grades of corn, although selling at higher prices per bushel, have been found actually cheaper sources of starch than the lower-priced inferior grades.

What are we dealing with here? This can go a few ways. Boruff paints the practicals as ignorant even though upthread he describes them as having wholly different production objectives. Were these backwards aboriginals that were thought devoid of technology yet somehow wanted for nothing and built an elaborate civilization no one noticed?

Again, this can go multiple ways. We’ve already found economic incentives for practicals to operate exactly as they did given their sellout culture. Dan Barber presents another angle in his lovely op-ed, Why Is This Matzo Different From All Other Matzos? Traditions can be a bit arbitrary and often they have unintended benefits. Part of the guided traditional processes framework is to make no assumptions of backwardness. Wine makers have found it a safe bet to assume brilliance in tradition and that techniques that survive were democratically selected for advancement even if it is not apparent. Dave Hickey won a McArthur for the concept if you need the art angle.

It is worth reading to the end of Boruff’s paper, but we need to go no further here. American whisky was fraught with cultural collision for decades after prohibition, well past Harry Harrison Kroll. Maker’s Mark clearly looks like the precedent that moves Bourbon past the creepy shortsightedness of C.S. Boruff et. al. and moves the spirit into the era of guided traditional practices. It took a while to capitalize, but this framework is where all of Bourbon’s recent prosperity comes from. There is still opportunity to do a lot more reflection and understand the place of all the new practicals popping up. Now that we better understand American whisky and its historic tensions, we can also reflect a lot more on comparisons to other spirits as their histories also start to fill in.

American Whiskey by the Numbers – An Unprecedented Look

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A unique mid century document came to me a few years ago containing the intimate but anonymous production parameters of 42 American whiskey distilleries producing 112 different whiskey mashes (85 Bourbons, 10 rye mashes, and 17 corn mashes). To my knowledge, the document is not known to any spirits scholars.

My plan to explore the document started with a scheme to unmask all the distilleries by tricking the conglomerates into matching their famous straight Bourbon labels to the old productions. I appealed for help, but didn’t get any interest, so it seemed like time to explore it another way. It was also complicated by the fact that these were just mashes and not labels themselves. Straight Bourbons could be picked out, but blends would be very complicated if not possible anymore.

Many brands making come backs have devolved into merely labels detached from the juice that was inside. As we will see when compared, many of the mashes were fairly redundant, featuring only slight variations. Brilliant progressive thinkers like Herman Willkie and Paul Kolachov were making production much more efficient in the name of environmental burden while also producing a great product. Their quest for genuine improvement was a big factor in the consolidation trend.

Distillery tourism is the new trend that may reverse the label detachment phenomenon and producers may be interested in de-consolidating their products back to more uniqueness so we have more places to visit, collect, and obsess over. The market for fine products and tourism make a lot of things newly viable, what we need then is a vision for style.

New players are entering the market that are financed well enough to be the truth seekers we need such as Kevin Plank’s Sagamore spirits. Sadly, they are starting with MGP, but they have picked up Seagram’s alum, Larry Ebersold. No doubt the parameters of gems like the legendary Baltimore Pure rye lie in the document. It shouldn’t be hard to spot the rye-est of all the ryes. Distillery no. 3, a conglomerate, made some brick house ryes, but distillery no. 38 made nothing but rye with one mash being a pure rye malt monster and their other mash being more econo.

To contextualize the document, I have reorganized it into a spread sheet that makes trends and patterns more obvious. I’ll do my normal barely appreciated dot connecting then hopefully some historians that have studied company timelines and have knowledge of the producer’s various labels can chime in and we can start giving probabilities of who is who. There are only two different wheaters and one corn producer using koji so it won’t be too hard to name the obvious. I’m hoping that Colin Spoelman swoops in and cleans up the list really nice.

The document gets specific and tells us the unique production parameters used by each distillery. Many only made Bourbon while others added a corn whiskey or rye and a few made all three. If they added that corn mash, they likely had a proliferation of labels for blends. Some mash bills were reused with different parameters and the spreadsheet lets us see that all comparatively. Most whiskey back then was commodity whiskey as opposed to the new fine market we see now and the document shows producers varying production parameters to make different crus, at least as blending stock, under one roof. This wasn’t the single barrel era yet. Who knows how they allocated production slots when they had multiple mashes in their repertoire. Some mashes were obviously modest while others were grander and some with a grand foundation were distilled to be a little lighter on their feet as supposedly was the trend.

The document was commissioned because fusel oil separation in continuous stills, the so called extractive distillation, was changing whiskey identity markedly. Only six of the forty two distilleries exclusively used batch distillation. Laws limiting distillation proof to imply character are all based on the assumption of batch distillation. A continuous still can be tuned so that its various side streams strip out the heavy character of fusel oil. Producers, no doubt led by Willkie and Kolachov, were also moving to advance fermentations, biological control, to alter much of a whiskey’s character pre distillation and aging (no doubt following the lead of rum, the most progressive spirit). The document was an attempt to mark a golden era of American whiskey before it went too wayward beyond “tradition”. Keep in mind, I may also be over dramatizing things.

For each itemized production, we have their:
•Mash bills, percent corn, rye, wheat, and malt
•Whether it was a sweet or sour mash
•Whether a lactic culture was added
•The percent of backset or stillage used to sour the mash
•The gallons per bushel of grain which implies alcohol concentration for the mash
•Duration of fermentation in hours
•I computed duration in days so we can think in terms of labor shift changes
•Plates on the beer still
•Min and max proof of the stripping run
•I compute the difference to imply how the still is refluxed to come to a relative equilibrium before the run is collected.
•Whether the doubler is a batch charge or continuous.
•Min and max proof of the doubling run
•I again compute the different to extrapolate a little more
•Proof of the final collected distillation
•Entry proof into the barrel.
•I compute the difference because the most grand brick house products will require the least dilution, just like a rum.

Corn is cheaper than other grains and too much corn in a mash bill can leave a rank taste at lower drinking proofs if distilled very low. It tends to be served above 80 proof to contain the flavor. In the era of the document, corn whiskey was still a thing, if not just for blending. Three distilleries exclusively made corn whiskey. One was still using the infamous ultra efficient and therefore cheap koji process developed by Dr. Jokici Takamine in the late 19th century. This is likely a Peoria Illinois producer, but possibly not Hiram Walker. Distillery no. 1 is likely the most heritage of all the corns. They still used batch distillation, though with a few plates, and no refluxing of the stills before they collected the run. Bourbons very high on the corn make me think of bottlings like Dant that I’ve tasted from the 1970’s that kind of sucked.

Higher rye content Bourbons, like Old Grand Dad is famously known to be, start to mark quality. Some whiskeys like example no. 3c were probably quite tasty. Distillery 3 was one of a few big conglomerates and it is interesting to compare their bourbons. Whiskeys 3a and 3b are subtle variations of each other and do not read as grand as 3c in terms of rye content, yet their fermentation times are slightly longer. Were any of these new acquisitions that were likely to be redundant and consolidated?

Speaking of conglomerates, distillery no. 3 is the most apparent, but the similarity of parameters in distilleries no. 5,6, and 7 make it seem like they were all under the direction of a single team. Could that be where Willkie and Kolachov come in?

Only two distilleries made Wheat mashes, and they loved their concept enough to make nothing but. One is Stitzel-Weller and the other is likely Maker’s Mark. Language in the document’s commentary implies that the wheaters are two distinct enterprises. Both distilleries used the same mash bill, the same single plate stripping still concept, similar lack of refluxing, and even the same barrel entry proof. Bill Samuels was known to acquire his recipe and receive assistance from Stitzel-Weller and the data could add conjecture to the extent of the help. My guess is that the more contemporary Maker’s Mark is the wheater that distills at the higher proof.

Malt is an interesting variable in a mash bill and it is thought only to provide assistance for converting starch to fermentable sugars, but it may also be stylistic judging by the varying proportions of its use. Malt is expensive and if a producer went heavy on it, they likely had a good reason. The highest malt content on the board is the 20% from whiskey no. 38b. That was from the rye exclusive producer and was matched with 80% rye which leads me to believe it was the Baltimore Pure Rye [*cough*cough* Sagamore, get on it! and talk to Wondrich about a three chambered still!]. I had been lucky enough to taste a bottle of BPR 1941 and it had a unique and dense maltiness very unlike any Old Overholt I had tasted of the same era. Overholt could possibly be derived in part from the ryes of distillery no. 3. which may be National Distillers (just a guess!).

Malted barley has a much higher diastic power than malted rye so when the malt figure is at the average, it is likely the more economical barley, but if it is as high as 20, it is probably decadently rye. Northern Brewer has started selling different malt extracts and their rye is quite singular. What would be cool to know is if there was a style of Bourbon mash that seemed like it was high on the corn, but was rye plus rye malt (instead of barley) so it really tasted distinctly high rye.

Few producers still made a sweet mash with two producers doing it exclusively. The rule of thumb with sweet mashes is that they can ferment faster and to higher alcohol contents than a sour mash. Distillery no. 2 made a sweet Bourbon mash, corn mash, and rye. Their rye is categorized as sweet but still employed 18% backset. Distillery no. 42 followed suit with two categorized sweet but also featuring 20% backset. The traditional quantity of backset for sour mash is 25% so anything less than that is considered sweet by the industry. Notice the first part of the rule of thumb falls part and distillery no. 2 happens to use decadently long fermentations though the second part holds true and they use a low gallons of water per bushel. Style points for no. 2! [that red three I think is their typo and should be a 13]

The addition of a lactic acid producing bacteria was something that surprised me when I first read the document. Co-fermentation of yeast with an innoculated bacterial culture is something that we think of in rum production, but here it was, thoroughly used in American whiskey and practiced for decades. I have yet to find an old research paper that focuses on it.

When you really get into it, the way they add their lactic culture is also very different than rum. Rum bacteria is all offense and aroma driven while sour mash’s lactic culture is all defense. Many inferior wild yeasts and aroma negative bacteria can not grow in the low pH medium produced by the lactic bacteria. Sour mash yeasts are unique and they used to be called wine-sour yeasts because they were selected for tolerance to soured mashes.

Innoculating with a lactic culture may seem high tech like sour mashers graduated from mere chemical control to full on biological control, to borrow some rum industry phrasing, but they were practicing it since before the 19-teens. They made it like yogurt. A small amount of a rye and malt specialty mash is held at about 120°. This temperature is beyond a yeast’s tolerance, but the lactic bacteria can grow and take hold. It wasn’t too fussy.

The bacteria basically infects the vat and accumulates in every batch to a point where fermentation is impeded and the vats must be chemically sanitized. These days under near complete biological control, some producers have advanced to the point where they have inline spectroscopy monitoring the beer telling them specifically if they need to clean the vats on the 18th, 19th, or 20th batch in the cycle. Too soon would be wasteful. If we get philosophical, we may even say that their involvement goes too deep. The windows for chaos are framed a little too tightly.

The sweet mash producers obviously did not add a lactic culture, but twelve sour mash producers also did not use it in any of their productions. These producers likely have a healthy variation of character during their production cycles and they tended to have smaller lineups such as one mash bill with variations of fermentation duration. I imagine Old Crow lying in this Bourbon philosophical territory somewhere. Its reputation was beyond the state of its production so the label was kept, but its mash bill was consolidated.

Gallons of water per bushel tells us how dilute the beer was and what its potential alcohol was. It also somewhat tells us how grand the aspirations of the ferment were. More water meant a larger mass to absorb the heat of fermentation which would keep the temperature down creating less aroma negative congeners that in the olden days would be a concern for batch distillation. More water also means more capital tied up storing the extra mass of the beer and far more energy used to boil it all in the end, so if you added it, the results had to justify it. Just like rum, progressive producers were migrating to temperature controlled fermentation vats and higher starting gravity fermentations to use less fuel.

There used to be legal minimums governing gallons per bushel (to promote hitting dryness) and even a provision for rum, but who knows where those ideas were by the time the document was commissioned. This relates to the idea of chemical control of a distillery. If you go way back, American excise officers used to actually help distilleries become scientifically competent. We just didn’t know enough about fermentation is those days and without care it was easy to get a fermentation stuck and squander potential alcohol before you distilled. The excise job would be phenomenally easier if all producers were guaranteed to ferment to dryness. The producer would also make more money and have less incentive to cheat.

When fermentation competence is the rule, the reason the excise job gets easier is because you can match potential alcohol from grain purchased to alcohol realized from the still. There will be losses but extrapolations can account for them. The excise officer becomes a stable pencil pusher and not a nosy detective with a flashlight only to find the distiller is incompetent. The scope of the IRS papers that keep turning up surprise a lot of people, but hopefully this explains their philosophy. Many of the excise guys no doubt loved whiskey. The bulletins they put out gave them a proper forum to influence the industry instead of being an annoying backseat driver on the distillery floor. I have written in the past about the public foundations of private spirits companies.

Longer fermentation times typically correlate to fuller flavored beers to distill (and there also used to be legal minimums aimed at helping hit dryness). This lesson is best learned in rum where there is a bigger spread in possibilities. In the document, we see fermentations as short as 52 hours for a corn mash and as long as 120 hours for quite a few others whiskeys.

One thing I did in the spread sheet was to convert the hours to days to look at the durations in terms of human labor cycles. Fermentation times weren’t exactly just carried out until specific congener targets were met, besides the obvious completion of converting sugar to alcohol. They were carried out until someone showed up to do the work of manning the pumps. If we look at distillery no. 27, an infamous wheater producing three variations of the same mash bill, they had a 72 hour fermentation, an 84, and a 96. In terms of days that is 3, 3½, and 4. So the question is, did they start with the objective of producing different styles or did it just happen when a runaway biological process met the rhythm of their labor cycles? Distilleries don’t employ a lot of people and that 84 hour ferment may have happened because he/she simply didn’t get to it yet. New distilleries are starting to encounter human rhythms dictating production practices while large distilleries have overcome aspects of it with automation.

If you know how to read things, the influence of a labor cycle can become a layer of our appreciation. I remember having a beer with a glass blower years ago, and across the room he spied a hand blown multi-globed light fixture. He said, “do you know why that last globe is darker than the others?”, “because he was tired.”

A new era was coming and it represents information not captured in the document (which might not really be true). All sorts of variables could change while producing roughly the same flavor if yeasts were more carefully selected or pitched in different quantities with different pHs plus a lot more options. They either specifically learned from rum, which was further ahead (*cough*cough* Arroyo!), or arrived at a lot of the same conclusions. There was a lot to gain. Producers could arrive at a product cheaper, they could reduce their environmental footprint which was a concern, or they could even make a product taste better.

Bourbon got pretty far without being too fussy about bio technology. Excise officers helped them out and the sour mash process took form without much more science than it took to make yogurt. They also grew and maintained fairly pure strains of wine-sour yeasts without owning microscopes. That was done using hops. Rum didn’t have hops to keep bacteria from their yeast and that is why Arroyo had to be such a thorough bio technologist (rum may have eventually picked up antibiotics). Lack of pressure led to lack of sour mash innovation. Arroyo was painstakingly conducting yeast Olympiads to find rum yeast champions employing large test fermentation arrays while Willkie and Kolachov didn’t hit the same level of science until probably twenty years later.

I’ve actually never looked into the specifics of Bourbon producing stills. I thought that maybe they flirted with fully continuous distillation and reverted back based on pictures I’d seen, but that isn’t exactly the case. The document differentiates between variables in the beer still versus what they label the doubler so it looks like the beer still is a discontinuous charge process while the second distillation is continuous. Multiple beer stills could feed a continuous doubler (but confirming that is still a google away). I could be wrong, I haven’t actually looked.

If a distillery operated a continuous beer still, and they definitely existed capable of digesting grain left in the mash, it would have between 12 and 20 plates. If a still had that many plates, they also likely wouldn’t need a second distillation. The most plates for a beer still in the document is 10 which is distillery no. 24 who exclusively made Bourbon. Mash no. 24b has a significant spread between the minimum and maximum proof so it is likely not continuous. Laws I’m not aware of may have dictated a double distillation scheme.

If their beer stills work the way I think, they had a typical heads and tales cut that was recycled. The plates, disclosed in the document, will somewhat correlate to the flavor passed on to the doubler, but not as much as the minimum and maximum proof of the beer run. Only three distilleries use a different amount of plates across their productions which could imply different entire stills in use or possibly just different columns switched on or off. Both wheaters use a one plate still which could imply a little more collusion.

I computed the difference between the minimum and maximum proof of the beer still run. The idea was so see if they refluxed the stills to bring them to relative equilibrium before collecting the run. A pot still is not at equilibrium and the run has a significant curve when you graph the proof over time so you see a big difference between minimum and maximum. A column still can be operated at relative states of equilibrium flattening out the curve. Collection from a column still can be paused by going full reflux, but the alcohol content in the column will increase. The ability to reflux means that multiple beer stills could be synced up with a continuous doubler even if they didn’t exactly heat at the same rate.

The document does not tell us about the cutting routines or the fraction recycling options the distilleries used. A heads cut from the beer still could be taken and recycled back to the next distillation run just like classic pot still double distillation and the tales cut could be collected in its own receiver instead of being passed on to the continuous doubler.

It would be so cool to see the same data from ten years prior. I suspect the industry was much more susceptible to trend than tradition. They all no doubt read the same research papers and bulletins especially with excise officers ever present and ever helpful. They likely also had consultants and I doubt anyone was too guarded which is how Maker’s Mark could emerge out of Stitzel-Weller without a scandal. I say that all by looking at the data and the industry research papers I’ve read that may have influenced the numbers. I don’t actually know any specific industry anecdotes. I have never particularly paid attention to American whiskey before so there is lots of room to add to or tear apart all my ideas here.

Continuous doublers must have been around for quite a while if so many people had them. There was probably a generation of equipment used right out the gates of prohibition that lasted maybe twenty years then everybody upgrading at the same time possibly as they exited the pressures of World War II.

You would think continuous stills would all be operated very similarly with very tight spreads between the minimum and maximum proof of distillation and quite a few producers had really tight spreads. Yet there is also a lot of variation such as distillery no. 14 distilling handsome seeming Bourbon mashes, but having a significant spread of 42 proof on their doubler relative to only 10 on their 2 plate beer still. Those numbers are very different than distilleries no. 5,6 and 7, which may all be the same conglomerate. The spread on 5,6, and 7 is as tight as the probable margin of error. Distillery no. 9 supposedly starts collecting from their continuous doubler at zero proof which may be possible if they are collecting steam and not allowing the column to come to any state of relative equilibrium before they collect their distillate (excise officer is rolling his eyes). There are some gaps in the data where distilleries did not answer the questions denoted by a “-“. It is hard to say if that zero should be taken at face value, if its an error, or if someone did not understand the question. The questionnaires were actually filled out by excise agents. Distillery no. 2 also operated their continuous doubler with unusually wide spreads. The wheater, no. 16, also did, but I am not confident in those numbers because they are exactly the same as used in their beer still while the second wheater’s, no. 27, are not.

Final distillation proofs and then barrel entry proofs are hard to read into. Classically, econo whiskeys and just plain junk were distilled at higher proofs to make them more palateable. Grander whiskey would be distilled lower, but then there was the trend to lighter on their feet whiskeys. At the same time, and the whole point of the document, was that producers were slowly learning to use their continuous doublers with the ability to easily separate fusel oil and changing American whiskey identity markedly. I bet there was even one infamous Bourbon that set the precedent while everyone watched in amazement. I would not be surprised if Kolachov had anything to do with it and it shouldn’t be hard to figure out what whiskeys had his name on them. All of the rules of thumb were falling apart. A new era of whiskey abstraction was dawning, special effects.

What I’ve barely mentioned so far is that all the data came with a commentary, but they don’t explain or explore pretty much any of the stuff I just presented. Their vantage point was much different. There is also lots of data I’m not showing because it is a bunch of boring congener counts. That data is boring but powerful. Columns could be added to the spread sheet with all the major congeners classes. We could then use econometrics and software like SPSS to find correlations. This would possibly generate statistically significant actionable advice such as increase the fermentation time if you want to increase the X and decrease the Y. We can leave that all for another day.

The authors were concerned with the potential of extractive distillation which is a method of fusel oil separation. Laws stating that distillation could not exceed 160 proof was not guaranteeing anything anymore. They were positing writing into law natural flavor standards for each congener class. The impact of extractive distillation may not have hit whisky yet, but the future comes at you fast. If natural flavor standards had to be created, they needed good numbers representative of tradition while they still were reliable.

The authors also explained a few bits and pieces in the data. The two curious “water-mashes” with no backslopping could make a whiskey lighter because less congeners are recycled by the backslop. They were also using early forms of GCMS and connecting chemical compounds to the infamous hog tracks of some new make spirits

The authors note that the maximum allowable entry proof was raised in 1962 from 110° to 125° yet average entry proof for Bourbon’s was still 109.8°. None of the bourbons were entered at the maximum allowable proof. That makes it hard to understand why the laws bother to change. The commentary section of the document has a table that compares various similar surveys conducted between 1898 and themselves. I have seen a lot of them and none are as comprehensive or have such an extensive table of mashing and distilling parameters.

It has often been stated that whiskies produced today are not as heavy or full bodied as those produced in the old days. To find evidence that would either support or refute this contention, a comparative examination of chemical data from the better known studies on whisky has been made and is shown in Table 7.

The data leads to the conclusion that not much has changed.

Possibly the heavier charring of the barrels resulted in the so-called “heavy whiskies” of the old days.”

It was a lot of fun to reflect upon and finally do something with this cool document which I am intentionally being partially vague about. Hopefully it will launch a few ships, start a few friendships and generate new chapters of American whiskey writing and scholarship.

Notes:

Wild Turkey was an non distiller bottler until the 1970’s and started as a supermarket brand.

Distillery no. 41 is likely Continental Distilling of Pennsylvania based on the 41C mash bill of 37/51/12 which is likely Rittenhouse Rye

Heaven Hill has used a 75/13/12 mash bill so they could be distillery no. 10,15, 18, 21 ,23, 24c, 25, or 30. Basically it is the most popular mash bill. Wild Turkey eventually became a 75/13/12 so they could be descended from one of these producers.

Distilleries 16 and 27 are likely Stitzel-Weller and Maker’s Mark.

Distillery 24 could be Four Roses because they do two different mash bills. Currently one with 75% corn, 20% rye, and 5% malted barley and another one with 60%, 35% rye, and 5% malted barley. The rye percentages could have changed from the days of the document as ideas in malt changed. Four Roses uses five different yeasts! Holy Biological control Batman!

Distillery 19 is likely George Dickel. Their current mash bill is disclosed as 84% corn, 8% rye and 8% malted barely which doesn’t match anybody. The document would consider them a corn mash producer and the only producer of quality doing exclusively corn mashes is no. 19. Dickel was a contemporary plant back then so it is probably not distiller no. 1.

Distiller no. 7 could be the Barton distillery because of the 75/15/10 mash bill that they claim to use today, but don’t forget they may some how be linke to distillery no. 6 because parameters over lap.

Today Maker’s Mark discloses uses the same mash bill as in the document.

Distillery no. 9 is likely Jack Daniels because of the 80/8/12 mash bill. Others used the same mash bill, but no. 9 was the only one that produced exclusively that. I’ll have to check the chemical data and see if there is anything odd that makes it look like its definitely charcoal filtered.

Distillery no. 17 is likely Brown Forman because of the 72/18/10 mash bill, but it looks like that distillery also ran a 74/16/10.

If distillery no. 3 is National Distillers, bourbon 3c could be Old Grand-dad, 65/25/10. These days the Grand-Dad mash bill is disclosed as 63/27/10.

Distillery no. 3 is likely Hiram Walker based on a paper about aging I’ve got where they used samples from three distilleries with proofs of distillation 154 for a rye, 118, and 127 for Bourbons.

If Michters at Bomberger’s distillery was always a pot still distillery, they could likely be distillery no. 41. but at the beginning I thought that was Rittenhouse. Which could mean they are definitely Pennsylvania Rye numbers.

A.C. Simpson, Gin Manufacture, 1966

I thought this paper was so good and so useful I’d retype it so it could be better indexed by google and more easily found. I have one more bulletin of blockbuster importance to write about before I write my annotated bibliography of gin. Amidst the document, I may input my own comments as quotations via the WordPress formatting.

My aim with all these documents is to raise the quality of gin from new producers. Remember, a high tide lifts all boats.

A.C. Simpson, Gin Manufacture. Process Biotechnology, October 1966.

Gin Manufacture
A.C. Simpson, B.Sc. joined W.&A. Gilbey at Harlow, Essex in 1956 as research assistant. In 1961 he was appointed chief chemist with general responsibilities for quality control and wine and spirit bottling.

The key factors in the manufacture of gin are the spirit used, the botanical formulae and the technique of distillation. Unlike whisky, the spirit used for gin should have no indigenous flavour, the taste of the final beverage deriving entirely from the juniper, and other botanicals. The present article, dealing primarily with the manufacture of London dry gin, also points to the differences between this and gins such as Steinhager and Borovicka.

Most of the gin produced and drunk throughout the world is correctly described as London dry gin: the description relates to the process and not the siting of the distillery. Holland’s gin, centred in the town of Schiedam in the Netherlands, is distinct in flavour and method of production. Plymouth gin comes from a unique distillery in Devon. A large quantity of gin is also made, generally for limited local markets, by various compounding and flavouring techniques. It is the manufacture of London dry gin which is specifically described in this article.

The word ‘gin’ is derived from the French ‘geniève’, meaning juniper: it is from this plant that the principal flavouring agent is drawn. Gin is said to have been invented by the Dutchman, Franciscus de la Boe in the seventeenth century, as a specific based on the diuretic properties of juniper oil [1 Encyclopedia Britannica]. Despite a medicinal origin, gin had acquired a reputation in England a century later which was the contrary in extreme. It had become the principal agent of drunkenness among the lower classes and notorious gin shops of the period displayed such enticements as ‘Drunk for 1d, dead drunk for 2d, straw for nothing’. Improvement came about with the retail licensing system and eventual concentration of distillery practice into the hands of a few large companies which developed individual strictly secret formulae. Lately the production of gin has been subject to scientific control in order to maintain uniformity in an essentially batch process.

By definition London dry gin is made from a relatively pure ethyl alcohol, flavoured by redistillation with various plant materials (botanicals) notable for their richness in essential oils. In a classification of spirits, gin is first cousin to liqueur and only distantly related to whisky and brandy, in which the flavour derives from the source of the alcohol.

Compound gin, made by the direct addition of essential oils to the spirit is inferior in quality to distilled gin. The property of dryness in gin is associated with degree of flavour: a very dry gin is distilled from a low proportion o botanicals.

Gin is classified for Excise purposes as British compounded spirit which can be manufactured from immature spirit and distributed to the public without a statutory age.

All spirits are defined for Excise, general trade purposes and retail in terms of percentage of proof spirit, a scale of alcoholic strength linearly proportional to percent ethyl alcohol by volume in which proof spirit has a specific gravity of 0.92308 at 51°F [2]. On this scale, pure ethyl alcohol equals 175.35% proof; and 70% proof, the normal retail strength of spirits is equivalent to 40% by volume at normal temperature. In the parlance of the trade the former strength is 75 op (over proof) and the latter 30 up (under proof).

Spirit
Gin production demands a supply of rectified fermentation spirit. The spirit much be clean and neutral in taste and odour and contain only traces of aldehydes, esters, fusel oils and other congenerics. The carbohydrate source of the spirit is generally grain (maize) but gin can be made from spirit of any source if it conforms to high analytical standards and is free from contaminant or congeneric odours. Spirit from molasses and, possibly, potato may therefore qualify (in Russia, spirit for vodka comes from these substrates). As the initial production of spirit is not an essential part of gin manufacture many gin distillers are not, themselves, producers of spirit.

This last paragraph is interesting because now there is the emerging idea that you can only be a “craft” distillery if you produce your own neutral spirits even if you probably shouldn’t create the environmental burden.

The basic spirit is made from grain by saccharification of the mash with malted barley and distillation of the fermented mash in a patent still. The methods and materials bear a close relationship with those of the grain whisky industry. A spirit suitable for gin is obtained from Scotch grain whisky by re-rectification.

I wonder what percentage of patent still whiskey production in Scotland is shipped to gin producers. Negligible or greater than 10%?

For the production of alcohol of good organoleptic quality from a fermentation spirit the fusel oils should be removed at the appropriate plate in the rectification column. Neutral alcohol is collected at the highest possible proof.

In North America, grain alcohol of extremely high purity and odour quality is produced in distilleries operating continuous, multi-column stills. Strict attention is paid to the conditions of fermentation, both in temperature control and sterility: the object is to maximize the yield of ethyl alcohol from a given weight of grain. The composition of the mash is regulated to secure good enzymatic conversion without the formation of much fusel oil. The spirit produced is adequate in quality for either gin or vodka manufacture. Some grain spirit made in Britain for gin retains an odour suggestive of its origin, due to incomplete rectification and purification. Many gin distillers who are not spirit manufactures rectify the spirit they buy before distilling it into gin.

It surprised me that they rectified. You’d think as far as energy usage went, it would make more sense to get it done to spec the first time, but maybe the industry was not that organized yet. I think the above paragraph is a shout out to Seagram’s.

Botanicals
The essential botanical of gin is the berry of the European juniper tree, Juniperus communis L; other flavouring agents come from a number of plants including coriander, angelica, orange, cinnamon, nutmeg, cardamom, orris and others. Juniper berries, coriander seeds and angelica root are probably common factors in the composition of all London dry gins but the proportions differ from one distiller to another. The ratio of the three main flavouring agents and the inclusion of other selected botanicals are defined by the distiller’s formula: an original combination which determines the character of gin. Distillers therefore do not disclose their botanical formulae.

Juniper berries [6] for the purposes of gin distillation are grown in Central Europe; the best berries come from the Chianti district of Tuscany but suitable material is also obtainable from Southern Germany and Yugoslavia. Berries from the Tyrol, Hungery and Czechoslavakia are generally utilised for local production of a juniper liqueur. At maturity the berries are smooth skinned, deep blue in colour and 5-8mm diam. Fruiting is biennial and the ripe berries are removed by harvesters who agitate the branches of the trees causing the berries to fall upon sheets laid on the ground. The berries are winnowed and carefully dried avoiding damage and fermentation, and sorted into culinary and industrial grades. The adulteration of berries with those of other species of Juniperus, e.g. oxycedrus is no longer so widespread because collection of the adulterant is no less arduous.

Gin I imagine demands the culinary grade of juniper?

Juniper berries are classified and selected for gin on the basis of appearance and the physical and organoleptic properties of the extracted essential oil (1.5-3.0%). Several components of the oil have been isolated and identified [6-8], by gas chromatographic analysis, Klein and Farrow [9] found 26.5% ∝-pinene, 9.0% myrcene, 8.8% sabinene and 3.8% limonene. It is to be expected that the components and the flavour of the oil will vary with locality and season: these factors are reflected in the physical properties of the oil on which the criteria of selection are based. For gin the berries should not give an oil with a predominantly terpenic odour [10]; the oxygenated compounds, in particular terpinen-4-ol, possess the aromatic flavour which characterises the best berries.

The criticism here of terpenic odor I think is why non communis Junipers are discouraged.

The second major botanical, the fruit of the herbaceous annual Coriandrum sativum [4], is cultivated in Russia, Roumania and other East European countries, for the supply of gin distilleries and the essential oil industry. The crop is also grown in the US, North Africa and surprisingly, in Essex, whence it is available to the English distiller after a good summer. Harvesting coriander demands judgement, for the fruit ripens sequentially and the farmer risks on the one hand an immature crop, and, on the other, shattered fruit with excessive loss of oil. It has been found that the crop contains the highest proportion of usable seed and quality of oil when the fruit on the central and first order umbels turns a chestnut colour [11]. The dried seeds (fruit) and 2-4 mm diam., number 100-130 to the gram and possess a perfumed but slightly cloying odour. Russian and English coriander seed yield 0.8-1.2% and 0.3-0.8% oil on steam distillation. As in the case of juniper berries, coriander seed is selected for gin on the physical properties of the distilled oil and organoleptic quality in dilute alcoholic solution. The main component of the oil is d-linalool (60-70%); other oxygenated compounds, geraniol, l-borneol and n-decanal are present [4].  Monoterpenic hydrocarbons occur (10-20%), principally as γ-terpinene, d-limonen and ∝-pinene [12].

The dried root of Angelica officinalis (Hoffm) provides a third important gin botanical [4]. The plant is cultivated in the temperate climate of Europe and the distiller’s requirement is met with the produce of an entirely cottage industry in the East German provinces of Thuringa and Saxony. The roots are plaited and hung up to dry: during storage changes occur in the yield and properties of the oil which becomes darker in colour, higher in specific gravity and lower in optical rotation and acquires a musk-like odour due to the predominance of high boiling lactones.

I’ve definitely over looked Angelica, but he’s totally got me with musk-like and high boiling lactones. Does it conform to anyone else’s experiences? A nice thing about Simpson is that he dares use sensory descriptors.

Other ingredients in gin formulae vary with distillery practice and are generally included in lower proportions, often only a few ounces in a charge of several hundred pounds. Common minor ingredients are: sweet orange peel (Citrus sinensis L.); bitter orange peel (Citrus aurantium L.); lemon peel (Citrus limon L.); cinnamon bark (Cinnamomum zeylanicum Nees); cassia bark (Cinnamomum cassia Nees); cardamom seeds (Elettaria cardamomum Maton); nutmeg (Myristica fragrans Houtt); orris root (Iris pallida Lam); and liquorice root (Glycyrrhiza spp.).

A few ounces to several hundred pounds is a big claim. I know a lot of new producers are trying to push supporting botanicals forward in search of distinction and perhaps they shouldn’t. Some of these material are particularly high in oil contents and perhaps have unique thresholds of detection so the addition may be far more than symbolic.

Small quantities of these botanicals may have a considerable effect on the flavour of the gin, being rich in oils of highly odorous composition. Orange oil [3] is 90% d-limonene and cinnamon bark and cassia bark oils [4] contain 60-70% and 70-95% cinnamic aldehyde. Other gin botanicals have been reported; aniseed, caraway seed, fennel seed, calamus root, geranium leaves, grains of paradise, turpentine and cubeb berries [13,14].

Many of the botanical ingredients described lose important quantitative and qualitative fractions of their oil on storage. Juniper berries stored a year for gin suffer a reduction of 20% in oil content and between 15 and 30% in moisture [10]. Coriander seeds lose absolutely 0.18-1.5% oil on prolonged storage at -14°C and 30% total oil in a year when stored in large hermetically sealed containers [15]. Citrus oils undergo autocatalytic oxidation when the peel is exposed to light and moisture [3]. Decorticated cardamom seeds lose 30% oil in eight months [5]. Stored botanicals are liable to insect infestation. Careful storage of botanicals by the distiller is necessary if he is to produce a consistently flavoured gin or avoid the evaporation of his flavouring material into the atmosphere. Ideally the botanicals are stored under temperature and humidity controlled conditions.

Distillation
The botanicals are proportioned according to formula and loaded into the still. A specified quantity of spirit, reduced to a strength of 80-100% proof is added (the exact strength depends on individual practice) and gin is collected as a definite fraction of the distillate. In Britain, gin distilleries and rectifying premises are not bonded but the still are secured by Excise lock and distillation of a set volumetric charge only is permitted. In North America, gin distilleries can be operated under bond.

The comment “the exact strength depends on individual practice” may conform to my idea that percentage alcohol in the still governs time under heat and that too low an alcohol content uses excessive time under heat (heating water you don’t need) while too high risks boiling the still dry.

The shape and design of the gin still and the manner of distillation constitute the third important factor in the manufacture of gin. The dimensions of the still relative to the volume and strength of the charge, the supply of steam to the jacket and cooling water to the head, determine the reflux ratio and hence the composition of the distillate. For a still of given reflux ratio and charge of specific composition the distiller modifies the production by selection of the middle cut of the distillate and also sometimes by a second distillation. Gin stills are built to exacting specifications by experts; and vary in capacity from a few hundred to several thousand gallons, measured to the level of the man-door in the pot of the still. The construction is always in copper and usually in the form of a simple pot still with tapering head which curves at the highest point into the downward sloping lyne arm (Fig. 1). The head may be expanded into a bulbous shape immediately above the pot. In some distilleries still heads are equipped with water jackets through which cold water is circulated during distillation; at another distillery a system of return flow conducts a preliminary condensate of higher boiling volatiles back to the pot of the still. All these features promote reflux in the course of distillation. The distillate is conveyed through a tubular condensor and is piped to inspection chambers for continuous measurement of alcoholic strength by means of in-line hydrometers; thence it passes to collection vessels. Stills are heated with steam generally applied to the jacketed base but some stills function with internal steam coils. Gauges for steam pressure, temperature of the liquid contents of the still, temperature of the distillate vapour and the condenser water are centralised in the modern distillery in a control panel.

The still head jacketed with water is sometimes called a “brandy ball” and is a method of providing optional degrees of reflux.

In operation the still is brought to boiling and the first few gallons of distillate rejected; this fraction is termed heads. Collection point for the middle cut of the distillate may be determined by an arbitrary quantity of heads, by the temperature in the column or by the appearance of the distillate. As the still charge is depleted of alcohol and steam pressure is raised to maintain distillation rate and when strength of the distillate falls to a predetermined value the still is struck and the distillate diverted into the second collection vessel. The still much now be exhausted of alcohol (tails) before the residue may be discharged. Combined heads and tails are called feints. The middle fraction of the distillate is gin, with a mean strength of 30-50 op. Still residues may be discharged to sewer after sedimentation and appropriate treatment. Feints are rectified in a special still with high reflux ration and the recovered spirit is added in constant proportion to the gin still charge. Feints may also be cleaned up by treatment with charcoal or potassium permanganate.

“by appearance” I think implies a demisting test where a sample is quickly taken and diluted to observe the degree of louching. This is correlated to how far has progressed and can probably be performed quickly enough to make a useful decision. The decision is gin product is of elevated importance because fractions are not recycled like other spirits. When the feints are recycled, they are stripped to neutral.

Alternative systems of distillation are sometimes adopted. In one variation the botanicals are place in a mesh tray above the liquid surface in the still. Volatile oils are extracted by heat and by contract with refluxing liquid but the botanicals so not undergo the maceration which occurs in the action of boiling. Some gin stills have been operated under reduced pressure.

What I haven’t figured out yet, is whether only the largest stills used gin baskets (my theory) because their time under heat was so long it compared to botanicals being boiled in a smaller still. Seagram’s early on was experimenting with partial vacuum.

In order to equalise the slight differences which result in the product of successive distillations in spite of the applications of rigorous quality control methods, gin should be blended in large holding tanks before transference to the bottling warehouse. Gin is diluted with distilled or demineralised water to bottling strength which in Britain is generally 70% proof. Water, free of dissolved solids, is used because otherwise the calcium and magnesium salts of hard ware are precipitated, giving sediments and chalky incrustations in the bottles [16]. Gin is colourless liquid and is often marketed in clear glass bottles. In order to attain the clarity demanded, gin is filtered (polished) before bottling, usually with cellulose-asbestos sheets in plate and frame or where throughput is large, with a filter-aid such as kieselguhr. Gin requires no period of laying down or maturation for improvement. The flavour derives entirely from the essential oils of the botanicals which are present in the condensate of the still. With gin the maxim might be ‘the earlier drunk the better’, for essential oils in dilute solutions tend to oxidise slowly with a detrimental effect on the flavour of the gin.

I think filtration and “polishing” are more important than some would think. I used to think polishing was only for dust and dirt but I think freshly distilled gin with always have errant out of solution terpenes that are some how emulsified and prevented from floating to the top. I’ve had big successes polishing very cloudy gins with sand (and there are lots of ins and outs of that), but the kieselguhr (diatomaceous earth) idea was new to me and I still do not exactly understand how it is applied. Stirred to attract particles then collected by the filter?

Analysis and quality control
The difference in flavour between well known brands of gin is distinctive even to the untutored palate. In order to maintain the distinction the distiller seeks to reproduce from one distillation to the next and from one year to another, a gin which is uniform in flavour. This is the aim of all producer of blended and compounded spirits but in the case of gin the process is more amenable to control. The whisky blender chooses from a wide range of finished whiskies, where as the gin distiller selects his raw materials and adapts his process to suit them. In the past, distillery organisation was based exclusively on the distiller’s palate and practical experience: today laboratory analysis and panel tasting play an important part.

I’m wondering if when Simpson says “where as the gin distiller selects his raw materials and adapts his process to suit them” he pretty much refers to scaling the botanical charge and blending stocks of botanicals to average out oil yields and their sensory properties. I suspect that the cut points stay as definite as possible batch to batch and the charges are reconfigured from different lots of botanicals to fit. And what of these master distiller’s? Do decisions at Tanqueray get made by the sole experience of a Tom Nichol or does he crunch numbers on the tasting panel, consult the analysis and paint by numbers? He did say recently that I make things too complicated. How far into the future are the international brands from the techniques laid out in this document?

The factors which determine the flavour in a bottle of gin have been described: spirit, botanical formula and technique of distillation. The distillation is a matter of control on the spot, with the still operator making adjustments in steam pressure and water flow from observations of the strength and rate of flow of the distillate. Modern distilleries utilise automatic steam valves, flow meters and other mechanical devices to obtain a precise control and the time of the entirely automated gin distillery approaches.

Did we ever get there? And if so, how small does it scale?

Botanicals and spirit were in the past selected wholly on the organoleptic evidence and while this method remains paramount in importance, it is necessarily supplemented by laboratory analysis. Control by tasting in the food industry has undergone a major rethinking in the last 10-15 years and the new methods are finding their way into traditionalist strongholds. In the US the standardisation of quality in distilleries through the use of taste panels numbering 20-30 persons is a widely employed technique [17]. Panelists are members of the distillery staff selected by test and they examine apparently similar samples daily in difference tests of the triangular or duo-trio type. Differences between the samples examined are expressed in statistical terms. Gin is amenable to this method of organoleptic examination because the accepted standard sample, properly stored, remains in good representative condition for a number of weeks. Panel tasting can be applied to finished gins as a test of uniformity, to spirit to check that it is up to standard and to dilute alcoholic solution of essential oils extracted from botanicals.

I was at a coffee roaster recently, Blue Bottle, and they were setting up panels for their quality control and every staff member knew how to quickly participate. I’ve tried to explain the importance to a few small distilleries and they just weren’t there yet.

Analysis of spirit has been restricted mainly to chemical methods: esters (expressed as ethyl acetate) by direct saponification; aldehydes (as acetaldehyde) using Schiff’s reagent; and fusel oil by the Komarowsky reaction. These methods give acceptable, meaningful results at intermediate and high levels of congenerics but approach the limit of accuracy when applied to the highly rectified spirits required for gin. It has been reported that the ‘fusel oil value’ of rectified spirits measured by the Komarowsky reaction is not necessarily an accurate measure of higher alcohol content but is a useful index of spirit quality [18]. Another widely used empirical measure of spirit quality is the permangranate time test which estimates the content of reducing substances by the rapidity with which a standard solution of potassium permangranite in contact with the spirit is decolorised. Ultra-violet spectrophotometry has been applied with some success to spirit analysis and provides a rapid instrumental assessment of inherent quality [19]. In Table 1 an analysis of an number of spirits used or proposed for use in gin distillation is presented together with a ranking of organoleptic quality by a small taste panel.

This all concerns the neutrality of the base spirit which is less of an issue now because it can be purchased from exacting specifications.

In the examination of gin botanicals for purchase or at intervals in storage, only juniper, coriander and angelica are likely to be subjected to a detailed laboratory analysis. The other botanicals would be distilled on pilot scale both individually and as ingredients in the formula and compared by taste against accepted standard. The essential oil of juniper berries, coriander seeds and angelica root are isolated from the plant material by steam distillation [20] and are measured volumetrically and for refractive index. The range of refractive index of the oil of juniper berries suitable for gin has been reported as 1.4840-1.4870 [10]. Lower values are indicative of a high content of low boiling terpenes which is undesirable in gin. Coriander and angelica oils should show refractive indices between 1.463-1.471 and 1.476-1.488 [4]. Ultra-violet absorption provides a rapid and valuable check of oil composition; juniper oil absorbs strongly in the region 220-240 mμ which is coincident in wavelength with a plateau in the absorption spectrum of terpinen-4-ol, and important constituent. Dilutions of juniper oil in 70° proof alcohol demonstrate an obedience of Beer’s Law at 225 mμ. Coriander oil begins to absorb at wavelengths less than 220 mμ but useful data are obtained if stray light factors are considered. Dilutions of the oil in alcohol are check by taste against standard samples. Moisture content of botanicals is determined by Dean and Starke tube.

New to me was that only the most significant botanicals were analyzed for oil yield and refractive index. I’ve slowly been doing a lot of work on the techniques and just found the block buster document on the subject from the horse’s mouth. Insignificant botanicals still get essayed but in an abbreviated form. I remember years ago tasting single botanical distillates from Citadelle, and each was startlingly beautiful with amazing focus and clarity of aroma. I thought that maybe they were prepared specially for the presentation, but they made have just been routine distillations performed for every batch of new botanicals.

Analysis of gin botanicals enables the distiller to base flavouring formula of his gin upon the definite properties of the batch in current use. Lots of berries or seeds with high and low oil contents may be blended together to give an appropriate intermediate level and a new season’s crop rich in oil can be phased into production with the least disturbance of the flavour characteristics of the gin. Purchase of botanicals each year from a range of samples supplied by the broker is made selectively on the basis of oil and moisture content, and composition and flavour of the oil in comparison with current stocks.

The finished gin is too dilute in oil to allow chemical analysis but control by tasting is supplemented by measurements of ultra-violet absorption. No published work exists on the application of gas chromatography to gin analysis but even with the most sensitive equipment, some preparation and extraction of sample is anticipated.

Other gins
Holland’s gin possesses a heavy, full-bodied flavour which derives not from the botanicals used in the gin distillation but from the original spirit; the gin character comes essentially from juniper berries but is overlaid with whisky-like congenerics. A mash containing up to 30% malt is fermented and distilled in a pot still with low rectification. The distillation may be repeated several times but the final spirit (moutwijn) does not show the neutral characteristics demanded for London dry gin. Originally the botanicals were added to the fermented mash before distillation.

Steinhager (Germany and Austria) or Borovicka (Hungary) is the distilled product of crushed fermented juniper berries [21]. It is twice distilled to a final alcohol strength of 70-85% proof. The stillage is and important source of oil of juniper.

Old Tom is a gin sweetened after distillation of approximately 3% w/v sugar. It is uncommon now in the English market but is still exported. Sloe gins, lemon and orange flavoured gins are made by steeping finished gin in the fruit or peel.

Acknowledgements
Thanks are due to the directors of W.&A. Gilbey Ltd for permission to publish this article; to Mr. M.S. Aldridge, distiller for his co-operation and Messrs M.G. Farey and C.C.H. Macpherson for analytical work.

References
1. Encyclopedia Britannica, 1964
2. Customs and Excise Act, 1952, Section 172(5).
3. Guenther, E. ‘The Essential Oils’, Vol. III (1949), D. Van Nostrand Inc. New York.
4. ——, Ibid., Vol. IV (1950), D. Van Nostrand Inc. New York.
5. ——, Ibid., Vol. V (1952), D. Van Nostrand Inc. New York.
6. ——, Ibid., Vol. VI (1952), D. Van Nostrand Inc. New York.
7. Motl, O., et al. Chem. Listy (1956), 50, 1282.
8. Hirose, Y., et al., Nippon Kagaku Zasshi (Japan) (1960), 81, 1776.
9. Klein, E. and Farrow, H. Dracogo Rept. (1964) 11, (10), 223.
10. Willkie, A.F et al. Ind. Eng. Chem. (1937), 29, 78.
11. Chikalov, P.M. Maslob-Zhir. Prom. (1962), 28 (2), 26.
12. Ibeda, R.M., et al., J. Food Sci. (1962), 27, 455.
13. Levin, H.J., Am Wine Liquor J. (1940), 7, 26, 33.
14. Jacobs, M.B., Am Essent. Oil Rev. (1949), 53, 54.
15. Rabora, N.V., Spiritovaya Prom. (1961), 27 (5), 13.
16. Warwicker, L.A., J. Sci. Food Agric. (1963), 14, 371.
17. Brandt, D.S., Lab. Pract. (1964), 12, 717.
18. Berganger, E., and Babel, W., Nahrung (1964), 8, 192.
19. Merke, R., et al., Branntweinwirtschaft (1960), 100, 479.
20. Clevenger, J.F., J. Amer. Pharm Assoc. (1928) 17, 345.
21. Stucklik, V., Sbornik Ceskoslov. Akad. Zeinedelske (1950), 22, 363.

Process Biochemistry, October 1966

Rare Vantage: Beverage History From The Spirits Chemist

I recently acquired another forgotten gin document, titled The History of Gin, by the chemist, D.W. Clutton, who gave us some of the most important works on gin distillation and chemical analysis. But what would such an important chemist speaking in 1972 have us know about gin? Read it and find out.

Clutton also wrote a wonderful history of rum that is notable and well organized. There are brilliant snippets and descriptions plus a bibliography of forgotten articles not seen elsewhere (that of course I’m already tracking down).

I also just digitized my copy of Herman Willkie’s Beverage Spirits in America —A Brief History (I apologize, but you will have to rotate the view of the PDF once you open it). This was an adaptation of Willkie’s 1947 address to the Newcomb society. It also answers the question: what would the greatest distiller of the 20th century have us know about American beverage history? And he goes on to say a great deal of things that were new to me. Some parts are so wonderful I dare not spoil them for you.

Clutton’s history of gin is really interesting and I’ll highlight what caught my eye. The most interesting parts are centered around Plymouth Gin and Old Tom.

J.B. Priestly described Plymouth gin as the gin ‘with a suggestion of a fresh morning at sea about it’.

The production of Plymouth gin is very localized. Messrs. Coates & Co. (Plymouth) Ltd. are the sole agents for its manufacture (with the exception of New Zealand, Germany, and Italy, where it is produced under license).

This was new to me and surprising as lately they hype their appellation status. More spirits are licensed for production in multiple locations than you’d think.

The secret of the success of Plymouth gin derives from the soft pure water which runs from the river Meavy, through the granite of Dartmoor. Spirit is obtained from grain whisky distilleries in Strathclyde, or occasionally from a London grain spirit supplier.

I began to wonder why he goes into such detail. Either Clutton was an employee or they just hosted him. It seems like Plymouth existed in a world where gin was simply a commodity but as often as possible they tried to elevate it to something fine.

During the war, molasses spirit had to be used, much to the disgust of the manufacturers. Eventually, however, the switch was made back to grain spirit, and this was commemorated by the following telegram sent from Glasgow—

From the land of Scotch and Bonnie Lasses,
We’re glad you’ve given up molasses
and Plymouth gin is once again,
The very best and made from grain.

The grain spirit is pumped into the still and reduced with the famous water to ca. 25° over proof and the spirit is rectified. The spirit is then pumped into a pot still and the botanicals are added. The centre portion of the distillation is reduced in strength, taken into bond and bottled as Plymouth gin. ‘Plym-Gin’, as it is affectionately called, is exported to 80 overseas markets.

The term ‘dry’, as applied to London dry gin, means that the over-all flavour content is low. This arises since the gin is distilled from extremely pure spirit and a low proportion of botanical ingredients.

I interpret “low” here as low enough to be crystal clear. If the gin is cloudy from insoluble terpenes, it either has too much flavour and/or is cut improperly. I’ve been exploring a new technique for post distillation clarification of cloudy gins and I’ve having spectacular success. It will be the defacto practice once I write it up.

Another explanation [of Old Tom gin’s origin] of the term was given by Boord’s (Distillers) Ltd. of London (Est. 1726) They established that Old Tom referred to Old Thomas Chamberlain of Hodges Distillery. He was an experimenter in gin flavourings, and once added sugar syrup to London gin. One of Boord’s ancient labels showed a picture of ‘Old Tom’ Chamberlain.

Old Tom is a gin sweetened, after distillation, to 3 to 6% w/v of sugar (or occasionally glycerine). Occasionally the sugar syrup is flavoured with orange flower water, and is known as capillaire. Old Tom is no longer popular in England, but is still exported.

This wonderful Difford’s Guide article gives even more background to the origins of Old Tom. I think its references mainly comes from a book titled Slang and its Analogs.

Clutton’s Rum had some spectacular passages I’ve love to quote, but I’m short on time.

Juniper Report: A Blog-Quality Survey of Academic Gin Literature

Feel free to skip to the very end if you get bored.

the first paper I found on Juniper was Controlling Gin Flavor by Herman Willkie and the team at Hiram Walker in 1937. Hiram Walker, I just noticed, was located in Peoria Illinois which is the same city as H. Shufeldt & Co. whom was an American producer of maraschino liqueur that was unearthed in the last post covering benzaldehyde in maraschino liqueurs from 1912.

Willkie explains new methods of standardizing the botanical charge to account for the varying essential oil contents of the botanicals.  He covers numerous testing procedures.  Most interestingly Willkie gives an introduction to the terroir of juniper and how it varies significantly by latitude.  He even gives some opinions.  Juniper expressions that Willkie did not enjoy I really enjoy.  This also led me to wonder if when recreating historic forms of gin such as Old Tom or Genever that we must consider their juniper sourcing.

In the limoncello article roundup where it was revealed that limoncello goes through no terpene separation and that terpenes and their unique distribution are the terroir of the product; what its all about. Terpenes got me thinking about juniper again and I wanted to see if there were any other great papers out there that would help connoisseurs understand gin and maybe even help new producers make the product of their dreams.

Numerous papers exist. Here is a bullet point run down of whats going on:

Characterization of Volatiles in Different Dry Gins from the J. Agric. Food Chem 2005, 53, 10154-10160 written by a Spanish team.

**they look at london dry gins and other “gins with geographic denominations”

**”When the production process takes place within a specific geographical area and fulfills certain  requirements concerning elaboration, composition, and quality, the gins can receive the denomination of geographical indication, as in the case of Plymouth gin (U.K.) and Mahon gin (spain).” I cannot not wait for “west coast” styles gins that match the ethic of west coast style I.P.A.s.

**G1-G4 are the top london dry brands while G5 is plymouth and G6 is Mahon. maybe we can guess the london dry brands by looking at some of their data. I bet they have tanqueray, beafeater, bombay or saphire? and I’m out of touch on what the fourth would likely be.

**they basically spend all there time proving that a method can detect compounds and how you need overlapping methods to get accuracy.

**”The highest contents of juniper characteristic monoterpenes were found in samples with geographic denomination G6, whereas sample with the geographic denomination G5 showed the highest concentrations of limonene and γ-terpinene. This is probably due to the use of citric species during gin aromatization.” so basically the spanish gin is my style and plymouth is boring and too citrusy.

**”In all of the samples, except G6, linalool was the most abundant among these compounds. Linalool is present in traces in juniper berries, whereas it is the major compound in the essential oil of coriander, in which it may represent >60%. Coriander seeds are well-known ingredients in gin aromatization, and linalool concentration may indicate the proportion of coriander employed for this operation.” … “The highest concentration of this compound was present in the London Dry Gin samples of the G4 group.” maybe that hint will elude to which is G4?

** there is a chart that quantifies the amounts of 66 different components in the six samples but I couldn’t get any great sense of the flavor from the numbers.

Comparison of a Novel Distillation Method versus a Traditional Distillation Method in a Model Gin System Using Liquid/Liquid Extraction from the J. Agric. Food Chem. 2008, 56, 9030-9036 by a team from Bacardi-Martini product development in collaboration with Clemson University in South Carolina

[Edited to add: It was explained to me by a well published, well patented mentor of mine that this study is likely a red herring. I wondered what incentive Bacardi had to publish it and it turns out it is likely just to support their patent application which they mention at the end.  The results are manipulated to build false novelty to justify a patent.  Things are presented in a way to throw people off. The model gins are not fractioned and the monoterpene level of the novel gin is never compared to other conventional commercial brands so you never get a true enough sense of the novelty on a chemical level.  They also never analyze what is left in their big ice chunk that represented the non-volatile fraction. The researchers are not naive and likely know all the finer points they should be pursuing.  The research went on to become the Oxley gin brand and I’m not sure if a patent was granted but I hope not. The process is not novel and spirits have been vacuum distilled for decades. Hopefully they cannot do anything to prevent smaller distilleries from experimenting with vacuum distillation. I should probably look into this more.]

**the novel distillation method was high vacuum distillation

**they studies a four botanical model gin composed of juniper, coriander, angelica, and lemon peel.

**”This research demonstrates the benefit of distilling botanical extract (particularly for the manufacture of gin) at temperatures below 0°C, which retains natural flavor of the botanicals better than under the traditional conditions, thereby producing a superior gin.”  this stupid statement sets the tone for the paper. they use two horrible oversimplfications: “better” and “superior”.

**in regards to traditional gin, “Some makers will apply a slight vacuum to get the distillation to take place at or around 60°C.” as opposed to 70-80°C.

**”The technical literature from the past 15-20 years has shown that vacuum distillation effectively circumvents high temperatures and reduces monoterpene formation in the final product” whatever that means.

**”Using a digital balance, 37.2 g of juniper berries, 52.8 g of coriander seeds, 18.0 g of angelica root, 10.8 g of dry lemon peel, 4270 g of 95% ABV GNS, and 687 g of deionized water were weighed and placed into a stainless steel pot and allowed to steep at room temperature (23°C) for 24 h.”

**for the atmospheric distillation: “and distilled until the thermometer reached 95°C. This insured that most of the alcohol had distilled at that temperature point.”

**for the vacuum distillation: “The distillation continued until the contents of the kettle froze, signifying that the majority of ethanol had been distilled.” cool!

**they acknowledge the significance of terroir on juniper berries when making comparison to other studies.

**vacuum distillation had a lower recovery rate than atmospheric distillation due to quite a few variables.

**they acknowledge “‘blow-by’, or vaporized alcohol that failed to be recondensed by the coldfinger and was passed out of the system through the vacuum pump.”

**”Coriander seeds (which are actually fruits) are normally the largest ingredient by weight in most gins.” is this really correct? their model gin had more coriander than juniper.

**linalool concentration decreased in the vacuum distilled gin post distillation relative to their un-distilled infusion of botanicals.

**vacuum distilled gin is a product with “less nasal pungency, more floral, less spicy aroma” So basically it is less of an acquired taste. Monoterpenes probably represent the most angular of junipers aroma components. To me, gin is supposed to be an acquired taste.

**they mention a patent application and that “proof of concept testing on a commercial scale is ongoing.” Bacardi who co-authored this paper owns Oxley Gin so this is apparently their feasibility study and Oxley is the product that emerged from the work. Why they would need to make this research public or team up with a university is beyond me. You would think they would have the capability and resources to do all of this privately.

Clutton, D.W. The Flavour Constituents of Gin, journal of chromatography, 167 (1978) 409-419

**”Dutch gin resembles the original gin produced in the 17th century, in that its flavour, reminiscent of almonds, is derived from the botanical ingredients and the source of the spirit used to make it.” I’m not sure how he comes up with “almonds” but Clutton is a big name in distillation research.

**”‘London’ relates to the method of production and not to the geographical location of the distillery; ‘Dry’ means that the flavour level is low.”

**their five samples varied and they only seemed to like one. others seemed to have flaws. who knows if they used famous brands.

**”UV analysis provides information on botanical flavour levels since juniper oil absorbs between 200 and 240 nm and coriander oil between 200 and 225 nm.” I’ve never seen UV analysis used and I’m wondering if there is anything low enough involvement about it that small distilleries could use it. An ultraviolet-visible spectrophotometer is only $1500 on ebay but knows how much time the testing takes to administer. They provide a chart which is pretty cool:

sample                   dilution       ppm juniper      ppm coriander     ppm cassia
1 london dry gin         1:1              45.8                   18.1                       —
2 london dry gin         1:1              27.7                     6.7                      0.5
3 london dry gin         1:1              37.5                   19.6                       —
4 plymouth gin           1:1              37.5                   24.6                       —
5 geneva gin              5:1              87.6                   26.2                       —

“The results show that the concentration of juniper oil in commercial gin samples varies from 25 to 50 ppm and for coriander oil from 5 to 25 ppm. The results obtained for Geneva gin (sample 5) must be regarded with caution since this product contains other species such as aldehydes, esters, etc. formed during fermentation.” …. “UV cannot differentiate between gin containing orange oil and those not containing this botanical, since limonene, the principal component, absorbs at 200 nm coincident with the absorption of coriander oil.”

“UV analysis only provides an indication of ‘total flavour level’ as ‘Juniper’ or ‘Coriander’. This is because the oils used for standardisation are steam distilled products, whereas gin is distilled in ethanol and part of the botanical flavour components are rejected as
‘feints’.”

So the technique has limitations. Here he acknowledges that steam distilled oils are un-fractioned unlike essential oils distilled with ethanol. In my distillation text I raised the same point in differentiating between distilled gins and compounded gins. One is fractioned and one is not. But from the above vacuum distillation study we also know that they may also differ significantly in degradation products (mono-terpenes) from time under heat. A steam distilled oil likely sees more time under head and higher heat than co-distillation with ethanol.

**There was some interesting stuff about odor thresholds and what constituents likely define the aromas but I’ll spare you. What is interesting is a chart they give that shows all the compounds then acknowledges what is at or above the threshold limit. This sort of proposes an active ingredient. I suspect though there are some flaws to the idea and there are all sort of synergies and interactions that change the threshold of perception. If compounds weren’t perceivable below the threshold they wouldn’t matter and it would be easy to compound things from only the “active ingredients” and I think that idea floated around in the artificial flavor business decades ago but the situation turned out to be more complex than that.

**A lot of their effort isn’t so much getting somewhere with the gin but getting somewhere with their analysis techniques. This was probably a pioneering a paper that opened up new analysis techniques to studying spirits.

**They spent a little time looking at how compounds like mono-terpenes accumulate in the heads and gradually decline. These compounds were the flaws of the vacuum distilled gin study. That study might have been biased if they never fractioned them in their model gin. So yes they are created but maybe you can remove them… The fractioning and selective
separation of this class of aroma component might be why big London Dry distillers expend so much effort tuning their stills.

**”GLC analysis shows that the early fraction of gin distillates are principally composed of juniper components. Coriander components distill over after a strength of approximately 75% ethanol is reached. Indeed a large quantity of flavouring components are run to waste in many typical distillations.” what I think he means is that fractioning is a big part of the gin distillation process but he is cheap and throwing away things annoys the engineer in him.

I wonder if before this era of analysis that even the big London Dry’s had a fair degree of inconsistency. This kind of research might have created an era of precision sculpted products that could meet global demand.

Sensory Characterization of Dry Gins with Different Volatile Profiles by a Spanish Team from Barcelona

**This study looks at 6 gins, four of which are London Dry and two geographic gins which are Plymouth and Mahon from Spain.

**They try and develop a sensory vocabulary and see if it can successfully be matched to chemical composition.

**The descriptors they narrow gin down to are juniper, citric, aniseed, spice, and licorice. These are all object comparisons and it would be interesting to see if the study could be done again with cross modal descriptors like looking at all the volatile components in terms of the gustatory division they converge with.

**They reference Clutton’s definition of gin from 1978.

**They mention other geographic indications I’ve never heard of: Ostfriesischer Korngenever, Genievre Flandres Artois, Hasseltse Jenever, Balegemse Jenever, Peket de Wallonie, Steinhager, plus the usual Plymouth Gin, and Gin de Mahon.

**They identify the sales of the brands which would help anyone positively identify them if they really wanted to.

**They make reference standard solutions of very specific volatile components that I would love to check out some time.

**They make other reference standards of things like paprika powder by simple infusion. Their choices were all things alleged to be in gin formulas.

**The initial list of descriptive terms identified by the panel in 3 gins during the session of vocabulary development. In bolt letters are the 10 preliminary selected attributes.

angelica root, aniseed, aniseed/fennel, aromatic plant, cane, cardamom, chili, citric peel, clean, coriander, cumin, detergent, eucalyptus, fennel, fertile, floral, fresh, fresh spice, freshener, fruity, herb louisa, juniper, lemon, lemon balm, lime, licorice, licorice root, orange, oregano, painting, polish, resin, rose grapefruit, rosemary, seaweed, seed, soil, solvent, spice, tangerine, thyme, varnish, vegetable spice, wood.

I see angelica root as converging with the same gustatory division as juniper which is olfactory-acid hence all those fresh and clean descriptors. the two combine with the intention of forming an overtone that is extraordinary as opposed to ordinary. citrus peel, fruity, aniseed/fennel, and licorice all contribute olfactory sweetness, but not with overtones so much as intervals when the citrus peels meet the anise. if rendered on an imaginary spatial scale, citrus and anise would be at opposite ends which is why experiencing the two together gives a sensation of depth and enlarged space. coriander is unique because it has qualities in common with the olfactory-sweet and the olfactory-acid so it influences overtones in both directions. spice can often be olfactory-bitter or olfactory-piquant. eucalyptus and licorice can also be olfactory-camphorous which is similar to piquancy and probably operates via the trigeminal nerve.

**descriptors were reduced to the five by a combination of examining frequency quotation and relative intensity. relative importance was then considered and then redundancy.

**”The results of the triangle test (Table 2) showed that the panelists could easily distinguish the gins with geographic indications (G5 and G6) and the London Dry Gin G1 (P<0.05). Gins G3 and G4, however, could not always be differentiated from the other samples.”

**they start to use some awesome spider graphs that I think should really be applied to cocktails. they give an intuitive look at how the gins different with some limitations. I should probably copy in the charts. the basically make it look like juniper does not dominate. the panel ends up searching for the other components and somehow makes them have out-sized intensity.

**”The geographic indication G5 [Plymouth] showed the highest intensity of citric attribute (Figure 3 and 4, Table 4). The intensity of the citric note in this brand was justified by its high levels of limonene and g-terpinene, together with linalool, which could contribute to the citric note (Table 5). On the other hand, G5 presented concentrations of juniper monoterpenes similar to those of G6 [Mahon] but showed the lowest intensity of juniper note by orthonasal perception. The high intensity of citric note in this gin brand could have masked the other attributes. The flavor perception did not depend only on 1 or 2 compounds on a complete volatile composition. Some interactions could take place between some compounds and also some compound could inhibit another, providing a different note.” I wish I remembered these gins better but I gave up on them years ago and now only drink and sell the local stuff.

**”The London Dry Gin G1 obtained the lowest punctuation for the juniper attribute by retronasal perception and was characterized by spices and aniseed notes. This gin contained the lowest levels of juniper characteristics compounds, while it presented significantly higher amounts of d-3-carene (P < 0.05). Also, the multiple regression analysis was performed. The spice note could be explained by a model with sabinene, d-3-carene, and p-cymene + ….; these compounds presented pepper and resinous notes, respectively (Table 5).

A paper I read won’t won’t quote is:

Effect of Latitude and Altitude on the Terpenoid and Soluble Phenolic Composition of Juniper (Juniperus communis) Needles and Evaluation of Their Antibacterial Activity in the Boreal Zone, J. Agric. Food Chem. 2009, 57, 9575-9584 by a Finnish team

The paper looks at the diversity of composition of juniper needles which are harvested for their essential oil which has a gin-like fragrance but also antibacterial properties.  The subject is not juniper berries but I suspect their properties parallel the needles.

As is mentioned by Willkie in the first paper, the character of the berries differs significantly with latitude. This paper adds altitude to the equation but find latitude is more significant.  Other papers I’ve seen add coastal proximity to the equation but I haven’t read them.  The most interesting gin I’ve ever made was with juniper from Cape Cod.

This paper and papers like it can add to gin connoisseurship.  We can now ask where the juniper has been sourced from and we can now ask to have gins made to reflect certain terroirs such as the northern most most juniper example.  Beer brewers already give us this with hops.  We also now know from the vacuum distilled gin paper that juniper Distillation involves the creation of many new aroma compounds through the degradation of precursor compounds.  Attention to detail with the cuts can refine the juniper expression.  Their paper might have been biased because they didn’t make heads cuts on their model gin distilled at atmospheric pressure.

A vacuum distilled gin isn’t without appeal, but I don’t think it should be touted as superior unless they are trying to give us a glimpse of a particular named juniper source.  Really interesting is the acknowledgement of partial vacuum gins which perhaps keep the temperature under a threshold. no brand was acknowledge. If I guessed I’d say Hendricks because they are the newest to the market and possible use new equipment that could handle such technology.  Bombay states the use of Tuscan juniper which is awesome but that isn’t going to mean much unless it is relative to other expressions that we know about.    Cascade Mountain Gin (the name might have changed), which sources their juniper from the world’s largest juniper forest gives us a three-fold unique expression. First its a wild foraged juniper from a distinct location. Second it is infused rather than distilled (or only partially?) so it was never degraded by heat making some of its aroma purity comparable to a vacuum distilled gin. And thirdly it was never fractioned so the outward lying juniper components that often get cut are in tact.  Other things like gustatory-acidity as still in tact which is why I think it is so enjoyable to drink neat. We end up with the pleasure of pondering; is its wild character due to being un-fractioned or due to unique sourcing? Lately it is my favorite gin.