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The Mezan XO Jamaica rum is likely the greatest deal in all of spirits at the moment, yet it has been slow to catch on. Even in this unprecedented era of spirits education buyers seem slow to discover anything. The product is a very smart blend likely assembled by E & A Sheer, who has unparalleled access to blending stocks. The product forgoes traditional coloring and subtle sugaring giving it a very sleek modern truth seeking quality.
Despite a righteous flavor and probable noble E & A Sheer heritage, the branding comes across as a vodka startup like veneer that may irk some. Don’t fall into that trap, the gates to MGP whiskey may be wide open, but access to the lost rums of the world is elusive and I recommend taking it any way you can get it.
This rum from Mezan has that je ne sais quoi, and that is appreciable quantities of rum oil, the most noble (if not divine!) of all the congeners. The new generation of spirits connoisseurs is slowly digesting the concept of esters, but the king congener class is the fairly high boiling point terpenes that are the product of glycoside hydrolysis (these are different from gin botanical terpenes). This is absolutely at the forefront of distillation research, being led by Cognac and also finds itself at the forefront of theoretical oenology where researchers are pointing to the same congener class as a significant layer of the terroir phenomenon.
You can fake esters, but you cannot fake rum oil. If you target esters in your production you will produce some rum oil, but if you target rum oil you maximize your potential and you get all the esters you want at the same time. This is easier said that done and was the dogged pursuit of the 1940’s rum researcher, Rafael Arroyo (it is pretty much what his 1945 book is all about). Production ends up requiring a virtuosic attention to detail or wild amounts of divine chance. It is hard to say how the producers behind Mezan XO do it.
Two distilleries can start with the same substrate and thus the same amount of glycosides yet end up with wildly different amounts of rum oil. This congener class can be seen as silent or bound aroma that needs to be unlocked with care. Glycosides are typically split via enzymes produced by yeast. Alt, non-sacharomyces yeasts produce far more enzymes than typical sacharomyces (think budding bakers or brewers yeasts). This is where our hero from other posts, Schizosacharomyces Pombe, comes in (as well as a few others).
Catalysts, like acidity, also act to increase rum oil production as well as that expensive ingredient of time. Longer fermentations (and resting periods) yield more opportunity for glycoside hydrolysis, but at the risk of aroma-detrimental bacterial infections. Risk is worth money and that is why we should prize this congener class. Authenticity is also worth money, and unlike esters, this congener class is something that cannot be faked. There is no easy road to rum oil.
We are building up to the Mezan XO challenge, but first we need to go a little bit further.
Many spirits of great repute have lost this congener class as their production has been scaled upwards because no one really knew where it originated. The main loss comes from migration to low risk pure culture fermentations adopted by many formerly traditional distilleries because typical sacharomyces yeast produce less of the enzymes needed to split glycosides. Besides spirits, this has profound implications for wine. Pure culture fermentations forgo a lot of this aroma because they result in a much narrower microbial community. For spirits, tequila may have been the most negatively affected by yeast changes as production scaled up.
Devastating changes to a spirit often happen when a distillery changes physical buildings as result of increasing production because so much of the microbial community is held in the architecture. Hampden estates, with some production areas covered in aroma-beneficial molds, is the perfect nth degree case study while others like the cult beer producer Cantillion are also notable.
So little basic science has been done on architecture embedded microbial communities that we don’t even know how they start or get balanced forming a SCOBY (I have a collection of anecdotes!). Aroma-beneficial molds are often over looked in Jamaican rum production in favor of aroma-beneficial ester producing bacteria, but they likely have their origins in the long forgotten “rum canes”. When Jamaican rum wash bills used percentages of fresh sugar cane juice, it likely came from Rum Canes which were canes infected with molds (also rat eaten or infested with boring insects). These could be analogous to the noble rot in wine grapes, but definitely different in the finer points. They might not even exist anymore having been eradicated by modern cultivation methods and pesticides and thus only available through the physical buildings we take for granted.
We’re getting closer to the Mezan XO challenge, but first we have to look at the end of rum science history in the 1990’s and how and why Cognac took over. Rum science seems to end in the 1990’s with a call to explore alt yeasts but never directly pointing the finger at aroma from glycosides as the most significant source of rum quality. Cognac picks up where rum leaves off for some really interesting reasons. This means that if we want to advance rum further we have to look to Cognac and some of the ideas at the forefront of oenology research.
Bon vivants will note that there is a lot of overlapping character between the finest rums and the finest Cognacs. Many rums historically were designed to mimic Cognac. Grapes used for Cognac production are also high in glycosides. Cognac production also has a few other properties overlapping with rum we could go into, but I’ll spare you.
Cognac oil as a congener class, just like rum oil, has been recognized for over a hundred years, but the big driving force behind why the torch was passed to Cognac is because they have their back up against a wall. Everyone else focuses on expansion instead of quality improvement, but Cognac is a small region and their product has been legendary for centuries. They have cultivated near all viable area. They cannot expand, they can only improve so that is where they spend their energies and do it quite well.
We can only hope the new American distilleries end up similarly with their back up against a wall. Right now they are all trying to expand rapidly, forgoing quality. If new American distilleries balloon from 600 to 3000, the focus will likely go from expansion to quality improvement as a way of staying competitive.
Cognac researchers are also notably in tune with their heritage and they bring us from an era of traditional practices to guided traditional practices. Chaotic diversified microbial communities are the hallmark of traditional practices and science is starting to recognize the importance of minority community member’s role of producing the rarest most extraordinary aroma. Tradition alone, in this context, is associated with ignorance and ideology best exemplified in the sloppy natural wines flooding the market. While guided tradition recognizes the science behind the chaos, does not seek to master it so much as frame careful windows around it to reign in the risk. The resultant products are consistently extraordinary (In wine, I would single out Randall Grahm immediately, but so many deserve cognition).
Before the Mezan XO challenge I’d quickly like to note that certain Armagnacs are very high in aroma from glycosides and they can be very hard to tell apart from Jamaica rums. Certain tequilas are notably high, but fewer than there used to be. Older rums from cult producers had it and lost it. Use your nose and keep track (there are also a few amazing chemical tests taught by Arroyo*). If we highlight exemplary producers they will become stronger guided traditionalists and be mindful as they scale up to global demands.
(*The most basic test is to take a 2 oz. sample and add sulfuric acid which will destroy all the esters and aldehydes subtracting their aroma. If strong residual aroma remains, it can be attributed to the rum oil congener class. This sample is now undrinkable!)
Rum oil, Cognac oil, and aroma derived from glycosides may have pharmacological effects, that is what the challenge is about. If you drink spirits high in these congeners you may feel significantly less dehydrated by the ethanol. Your buzz may seem to hang broadly in a really lovely way. It is a different drunk with lots of anecdotal evidence to support it. Search your recollections, have you ever experienced something like it? Is rum oil the pattern behind mysterious lack of hangover after significant consumption? Are wines of terroir more gentle?
Most all congener classes have been widely studied and ruled out as specifically contributing to hangovers in broad populations. Rum oil has not been studied because of near no awareness and that it is appreciable in less than 1% of all spirits. It is the product of very specific microbial communities just like so many drugs, there is no scientific reason to immediately dismiss its unique potential power.
Remember, I am the guy perceptive enough to have identified all of the olfactory illusions in the wild categorized by Richard Stevenson. When wallowing through subjectivity, my track record of acuteness rivals a neurologist.
I encourage any devoted bon vivant to take the Mezan XO challenge and consume appreciable amounts of the spirit (safely) and note the effects. Do this especially if you are aging and your tolerance for alcohol is changing negatively hangover wise. Who can afford to crush eight ounces of Martel Cordon Bleu, but anyone can afford Mezan XO. Sacrifice your body for speculative science. Design controlled drinking experiments. Supply of truly fine spirits will not come without demand and here I am unraveling the chemical pattern. No hangover research has been focused enough to look at a mythic congener class that is barely acknowledged and not widely available on the market. Maybe we can inspire researchers to pursue it. What comes before the science? This.
Take the Mezan XO challenge and/or search your recollections then please leave a comment!
[A vodka company is validating some of the ideas. Spirit gentleness on the body is not so much about what a spirit doesn’t have, i.e. vodka, but possibly what it does have. Congeners matter.]
4 thoughts on “Spirits Review: Mezan XO Jamaica Rum”
i found this french paper after reading your article. You might find it intersting
Wonderful stuff in there. Thanks for sharing. Its amazing that google translate is opening up a new world of literature.
Very few people are talking about this congener category, but papers like that are very encouraging. Cheers! -Stephen