Deconstructing Popular Aromatic “Bitters”

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[Dehydration of small samples to isolate non-volatile components and their gustatory properties has become an important tool in my product development kid]

Recently I was asked if there was a significant amount of sugar in Peychaud’s, Regan’s, or Angostura bitters. I didn’t know the answer, but I did know how to find out. The process of revealing the sugar content would mean sacrificing an expensive amount of product, but there might be numerous other valuable things to learn as well so why not?

My methodology was not that rigorous due to unfortunate constraints. I started the project at work where there is no scale, so the samples started as volume measures taken with an angled oxo jigger and then ended up being weights when I recreated the volumes later and weighed them. I thought I’d be able to measure the density of the samples with a hydrometer as well, but the sample sizes I used proved to be too small. Hopefully the results may motivate someone to redo the experiment with larger sample sizes and sounder methodology.

The five ounce sample of Peychaud’s bitters turned out to weigh 128 grams. Fully dehydrated the extract weighed 1.2 grams which is 0.94% of the original weight.

The five ounce sample of Regan’s bitters turned out to weigh 122.2 grams. Fully dehydrated the extract weighed 0.8 grams which is 0.65% of the original weight.

The five ounce sample of Angostura bitters turned out to weigh 124.9 grams. Fully dehydrated (some sort of liquid remains) the extract weighed 16.3 grams which is a whopping 13% of the original weight.

This table from Joseph Konig which I’ve linked to before shows the extract level of angostura bitters from 1879. The extract appears to be 5.85g/100g of solution which, but this number includes sugar. The sugar content was 4.16g/100g of solution which yields a “dry extract” (sugar free) of 1.69 g/100g of solution. These numbers make me wonder if they used any emulsifiers to hold everything in colloidal solution back in those days. Back then, Angostura bitters had 49.7% alcohol which is higher than today. That sugar content also ends up being 41.6 g/l which seems pretty high and makes me also wonder if it had to change as potability of bitters was enforced differently over time. There is also a chance that the sugar encountered was not sucrose making it the odd man out in Konig’s table so its perceived sweetness might be much different than the other products. Sugar is listed in the ingredient list of Angostura bitters, but who knows how broadly that term can be used.

The samples were then reconstituted back to five ounces with distilled water and measured with a brix refractometer. Brix refractometers are only calibrated to work for water based solutions which is why the bitters could not be measured while they still contained alcohol. Both the Peychaud’s and Regan’s bitters had a brix measure of less than one, but the tool is meant to measure brix at ranges much more significant so its hard to say if the measure means anything.

Angostura had a brix of 8 with the refractometer, but the refractometer was likely confused by another substance with a similar refractive index. Under circumstances like grape juice for which the tool is designed, 8 brix would indicated an estimated sugar content of about 80 g/l. Looking at the dehydrated sample there is no way there is that much sugar present. There probably is no sucrose. Some sort of liquid actually didn’t evaporate from the extract (why it weighed so much) and it might be glycerol ester of wood rosin which is a common food additive. Angostura bitters has so much stuff to keep in solution that it probably needs an emulsifier. Previously I had spun a load of angostura bitters in the centrifuge for 20 minutes at 5000 g’s and it didn’t budge an inch. I was hoping for a lot of sediment and got none which might also indicate a powerful emulsifier is present.¬†[the additive it turns out is a surfactant used to keep aromatic compounds called terpenes in solution. Other bitters should probably be using them, especially citrus stuff which is sensitive to terpene loss]

It should also be noted that as the Peychaud’s sample was dehydrated, the anise quickly evaporated and was taken over by a spectacular aroma of berry-like fruit. Peychaud’s might be based on an anise-fruit combo just like the Spanish liqueur Patxaran which pairs anise and sloeberry (my absinthe formula uses the same aroma system!). Most bitters are produced by infusion, so if the aroma of fruit was present there might also be the sugar and acid of the fruit left over in the extract, but the sample had nothing. If they put a fruit aroma in Peychaud’s bitters, it is either compounded from an extract or from a distilled eau-de-vie that makes up the base spirit. A motive for distilling the fruit aroma could also be to create the final color which may be adversely influenced by a fruit infusion.

I didn’t really get to taste these deodorized-water based samples (which I regret) because I wanted to dehydrate them again and refortify them to the same proof with a neutral spirit (they also do not reconstitute perfectly with room temperature water). I guess I could have done that with a smaller volume, but I didn’t have the forethought. Tasting the deodorized samples without the distraction of their alcohol content may reveal something about the gustatory-bitterness of each product and may be a useful experience for those producing their own homemade bitters.

Once the samples were again dehydrated, I reconstituted them back to their original volumes with the original alcohol contents. The alcohol content was recreated by diluting 50% alcohol vodka to match the alcohol contents printed on the labels. The samples now are more or less completely deodorized. Experiencing the samples now may teach how the gustatory sense (bitterness), haptic sense (tannins), and piquancy define the products. The samples now can be tasted without aroma modulating gustation.

Deodorized Peychaud’s has no distinct gustatory-bitterness and comes across more or less as fuschia colored vodka.

Deodorized Regan’s has a definite sharp gustatory-bitterness.

Deodorized Angostura bitters is some interesting stuff. Once the colloidal solution (I think its a colloidal solution?) is broken, it can’t really be properly reconstituted. I unfortunately didn’t have a large enough sample to run it through the colloid mill. True, Angostura bitters does have lots of aroma, but it is also very much defined by its impact on the other senses. Astringency might be the greatest attentional feature, followed by a cinnamon-like piquancy, followed by subtle gustatory bitterness.

Usage of the term “bitter” seems to be very much in flux over time. The similar term “acrid” has also evolved over the years. Acrid now most likely refers to extreme aromas like concentrated acetic acid, bleach or ammonia. In the 18th and early 19th century, likely before the widespread availability of industrial cleaners, the term acrid referred to the aroma of botanicals like cloves, cummin, mace, and nutmeg. Sweet vermouth or Benedictine would be described as acrid and that would not be a negative.

Many academic studies of sensory science describe a confusion of the term “bitter” where the term also gets attributed to astringency (because of our lack of a broad culinary lexicon). Angostura bitters may be labelled bitter when they really are most predominantly astringent.

Angostura bitters may also exhibit a different type of “bitter”. The term bitter today seems to refer to extreme bitterness like wormwod, gentian, and quinine instead of mild bitterness like that of cloves. The usage of the word has taken a similar tack to that of acrid. Barb Stuckey, in her excellent new book Taste What You’re Missing¬†describes a study where pregnant women develop significantly increased sensitivity to bitterness and interestingly a notable aversion to cloves. Though mild enough that few people today would easily classify them as bitter, cloves according to pregnant women are bitter and the clove-like characteristics of angostura bitters might make the name “bitters” fitting though in a usage that is no longer common.

The success of Angostura bitters may come from their ability to stimulate the trigeminal senses. Stuckey describes a study where the elderly are given samples of grape jelly. They cannot identify the aroma because those chosen for the study have lost their ability to normally control retronasal olfaction (also known as mouth smelling). Chilies, which contribute piquancy, a trigeminal sense, are added to the jelly and the elderly in question are suddenly able to identify the aroma as grape. Apparently sometimes mouth smelling has to be turned on and it is triggered through pairing the senses.

The senses that operate via the trigeminal nerve seem to turn on and awaken mouth smelling really well. Like piquancy, the haptic sensation from tannin operates on the trigeminal nerve turning on mouth smelling as well. The astringency of Angostura bitters may be a mouth smelling trigger in certain situations.

In the maraschino blackberry illusion or the Fernet aromatized cherries I’ve made in the past, the haptic sense (think texture) has been shown to create dramatic amplification of aromas. The maraschino blackberry illusion presents two “liquids” which are both the same in sugar, acid, alcohol and aroma (blackberry & mace). One liquid is plain; a liquid while the other is suspended in the body of a blackberry which essentially creates a structure of stuck together “pods”. The mace is barely detectable in the plain liquid while in the fruit body, the extra haptic data makes the aroma roar!

One sentence to take way: The salient feature that makes Angostura bitters so world renowned and awesome is likely its sublime astringency.

****continued****

I finally measured the specific gravity of a nice sized sample of Angostura bitters. I came up with 0.97596. Unfortunately, I cannot find any other measures published on the web to back up my number. I did find some nutritional information for angostura bitters published on drinksmixer.com. They cite a sugar content of 3.7g per one ounce serving (nutritional information from other sources was all over the map in terms of figures). This figure becomes 125.06 g/l, but who knows how accurate they have to be and if they are referring to sucrose or not.

The specific gravity of a 44.7% alcohol solution is 0.94403. This means that something influences the specific gravity by 0.03193. It takes 83 g/l of sugar to influence a specific gravity by that much. So where are we? I’m not exactly sure, but that number does align itself well with the brix reading taken above via the refractometer, but the sample did not crystallize like sucrose usually does.

I dehydrated a 250g (260ml) sample down to the solids and the liquid sugary stuff. I then reconstituted it with El Dorado 75.5% (151!). My thought was that the high proof might force certain things out of solution such as in the case of my Fernet 151 project. After seeing a dehydrated sample of Angostura bitters rehydrated to its original proof, I thought I’d also have to send it through the colloid mill to put it back together. The 75.5% alcohol rum miraculously reconstituted nearly everything; no agitation required! There was scant amounts of residue left on the bottom of the container (but I do not think it was due to not being soluble). Apparently, whatever numerous components make up the soluble non-volatile portion of angostura bitters, they are very much soluble in alcohol.

It should be noted that the end result is also delicious. The bitters were essentially de-odorized by dehydration, but the high proof reconstituted result still has all that same fun cinnamon-y-ness. It even feels much smoother than the El Dorado 151 alone. I will have no problem drinking the experiment.