The birectifier is stirring up some old lingering ideas and pursuits. One of them relates to why spirits get sugared. The reasons will confirm a lot of peoples’ beliefs, but we’ll also examine the converse phenomena of tart spirits. The title refers to the idea that heavier pot distilled spirits are turning up a lot more volatile acidity (non-acetic, and perceived by gustation) than I would have thought possible. This is not the easiest thing to detect in its natural state because so many other sensory features vie for your attention. A strong bet is that this is mainly lactic acid. The latter fractions of the birectifier and the stillage of some of these spirits can be tart like lemonade. But how does this relate to sugaring?
Spirits meant to sip are basically sugared when they have no acidity and too often no nobility. They’re flabby to borrow a term from wine which refers to acid deficiency. These spirits are also pretty much hollow from an olfactory high value congener stand point so they shouldn’t be worth much money.
To commonly enjoy a spirit at room temp, we require some sort of gustatory feature, and apparently sugar is an easier contrived choice than adding acidity, though various acids have been historically added. When we accept spirits that have no distinct gustatory feature to latch onto, like vodka or gin, we commonly chill them down and let extreme thermoception become a stand in. It works.
A continuous column spirit, which implies a higher distillation proof (and stillage, but no tails fraction to recycle), would be far less likely to have significant volatile acidity (remember, we’re talking non-acetic). Birectifier fractioning confirms it. Ferments we typically batch/pot distill have significantly higher noble volatile acidity than spirits we send through a continuous column. Pot still ferments are also typically engineered to produce more high value congeners like fixative terpenes (rum oil [damascenone, damascone, ionone]) and noble long chain esters.
This all intersects with fads to some degree. We are squarely in the realm of acquired tastes and drinking pot distilled spirits like Mezcal is quite fashionable. People are accepting tart spirits when previous generations would probably prefer their commodity flabby blended whiskies, and on the rocks. Or, maybe with soda water to make them less flabby.
I don’t really think that anyone is nefarious and suspect that certain rum producers are deluding themselves just as much as anyone could say they are cheating consumers. I think they are out of touch, out of ideas, and probably could not articulate these sensory patterns. Consumers are ready to pay top dollar for nobility, but many producers likely face a generation gap and do not have the know how to produce ferments worthy of a pot still now that demand has returned.
But, could sugar ever help produce a noble pattern? What if you had a pot distilled blending stock with absolutely remarkable persistence and you stretched it with a sizable amount of continuous column rum to make it affordable and match the appetite size of a market you are responsible to serve (distillers have responsibilities we don’t give them credit for). Now, the rum oil absolutely sings unimpeded, but you have no distinct acidity, what do you do? Is this relegated to flabbiness and doomed to a life of mojitos? (not a wasted life). Or, do you bump it with a smart boise?, sugaring it and adding barrel extractives like you learned from Cognac.
There is easy possibility of a noble type of sugar structured rum, but I don’t think we are seeing it. The last few I’ve analyzed with the birectifier were colossal let downs with naked fractions 5’s (no HVC’s).
I think we resolved some things with rum, but we opened a lot of questions about Bourbon. How much lactic acid is volatile from the sour mash process and how dramatically would the same continuous Bourbon column still product differ if it were pot distilled? Bourbon likely dodges a lot of acidity by continuous distillation and then creates sufficient structure by using new oak. Older pre-prohibition styles of Bourbon likely had far more volatile acidity influencing structure and there are many data tables we could look at to corroborate things. The effect of this volatile acidity on gustation may be more salient than other notions about past productions of older whiskies such as fusel oil differences.
Acidity is a phenomenon worth considering in spirits and the birectifier really highlights it. I do not think people realize how significant it is. The main motivation behind sugaring spirits may be to provide a gustatory feature when acidity is not present so that spirits can be harmonious at room temp and not feel flabby. The tradition of chilling spirits may also help to add the perception of structure when there is an absence of distinct gustatory features. There are many ways to skin the cat and any should be justifiable as long as you’ve got high value congeners.