Follow along: IG @birectifier
What this post is really about for me is testing the birectifiers I produced myself in my glassblowing workshop. I am about to release a birectifier I produce myself with a dramatically lowered price. I’ve sunk countless hours into this passion project.
I’ve been collecting fun case studies to work through. This birectifier performed well. It generated a few degrees of additional reflux than the original model I use and you can tell this because it took slightly more energy input (% of 115V) to collected each fraction at the traditional pace of 25 ml / 15 minutes. This difference is observable but probably not that important in the grand scheme of operation. However, I do need to change the angle of the fitting that connects to the condenser.
A few years ago I won an auction full of Jim Beam decanters. Nearly all of them were from 1971. I already drank all the ones that had a very good fill level, but then transferred all the decanters damaged by extreme evaporation to canning jars for future projects.
This particular decanter had 31% evaporation and the ABV had been reduced from bottling at 43% to 39%. It is hard to say what we could learn from this case study of a damaged whiskey, but I could surely use it to test my new birectifiers. The 39% ABV sample took 256 ml to fulfill the 100 ml of absolute alcohol required for analysis.
When you start heating your distilling flask, the heat controller displays a number that represents a percentage of 115V electric current. Typically, I can collect my first fraction at an energy level of 42, but this birectifier was demanding 44 which is again observable but likely not significant. It may also be correlated to other external variables like room temperature and humidity. I’m trying to be rigorously knowledgeable of what I’m producing and my ability to limit variation. I have the advantage of being both the glassblower and knowledgeable operator.
What would damage look like? Besides ethanol loss, my best guess is that ethyl acetate evaporated and the spirit would have far less than the average 8-10 year old whiskey. Distinct iso-amyl-acetate implies this spirit was column distilled as expected. In a column, acetic acid moves through zones where higher alcohols have congregated increasing the probability of forming this ester as opposed to basic ethyl acetate. A pot still has less probability of this happening. Iso-amyl-acetate can be a feature in some spirits, but a flaw in others when it is too salient.
[I may be wrong about this assertion. I was implying a doubler that had features of a column like fusel oil extraction, but I may be very much incorrect. The aroma, however, is unmistakable. In Beverage Alcohol Production (1982) it is described that iso-amyl alcohol accumulates on plates with much lower proof than other higher alcohols like iso-butyl and N-propyl.
That text describes:
Iso-amyl alcohol accumulating at 125 proof
Iso-butyl alcohol accumulating at 154 proof
N-propyl alcohol accumulating at 166 proof
It also describes the phenomenon of continuous doublers accumulating excessive acidity in their 25 proof stillage and needing to be drained every couple of days. If iso-amyl acetate isn’t some weird artifact of this decanters aging odyssey, it may have accumulated due to the unique nature of iso-amyl alcohol relative to other higher alcohols and a doubler that had operated long enough to accumulate volatile acidity (skewing the reaction kinetics). Please fill us in if you know anything about this subject.
A little more information came in that the iso-amyl acetate could have accumulated from a variety of places. The first may have been hot quick ferments where it is simply produced in the ferment. Second may have been drifting of the yeast strain. Third may have been a “flooded” or “drunk” doubler. I was informed that Jim Beam used traditional Bourbon stills and only in the early 1990’s switched to a stainless doubler. I would have thought these doublers would continuously drain to a certain level, but the exact mechanism they are controlled with isn’t remembered by any sources I had.]
We do know from the 1967 IRS survey, these bourbons were distilled at an average of 60% and barrel entry proof averaged 55% (despite being legally allowed to use a higher entry proof starting in 1962). This may explain the degree of volatile acidity in the spirit. In years since, distillation ABV has crept upward to make lighter whiskey and so has barrel entry proof.
The fifth fraction of this spirit was very strong and contained obvious Bourbon identity. I don’t have enough experience to say what percentage of this aroma is derived from the new make distillate and what percent is from volatile oak extractives. Arroyo presented the idea that the birectifier could be used to look at spirit maturation in oak. If we examined spirits from similar new makes across years, it may be plainly obvious what volatile congeners were being extracted from wood. Studying this may help us find points where we can confidently say maturation is maximized and point us to other ideas such as a starting acidity speeding up aspects of maturation. Organoleptic analysis with the birectifier may give us better rules of thumb for how this happens than pricey, hard to interpret GCMS.
After birectifier analysis, I had about 250 ml of evaporation damaged whiskey with nowhere to go and fractions representing concentrated congener groups. I blended what remained of fractions 1 & 3 (a combined 40 ml) and added them to the whiskey until my 43% ABV (86 proof) spirit bubble sank. I was able to raise the ABV back to bottling strength and return a fair amount of the particular congeners lost to evaporation. The result was particularly delicious. This was only an off the cuff estimate of restoring the spirit, but was right on the money and particularly drinkable.
Fraction 1: Not concentrated to the point of non-culinary aromas. There is a distinct extra fruitiness beyond ethyl-acetate that my guess would be iso-amyl-acetate which brings a banana character. I’m also guessing some of the congeners in this fraction blew off with the high sample evaporation (31%).
Fraction 2: A diminutive version of fraction 1 as expected. The banana character becomes more focused and easily namable.
Fraction 3: Fairly neutral as expected but I feel lingering iso-amyl-acetate.
Fraction 4: Detectable fusel oil. Not as sharp and wraith-like as I expected from a Bourbon. I’m not certain any higher alcohols could have been lost due to the high sample evaporation.
Fraction 5: Louched with large droplets on the surface. Undeniable Bourbon identity. Almost subdued. Is this distillate aroma or oak extractive aroma? Not as sharply floral as a rum despite the visual queue. Palatable but slightly acrid. We will have to let this evaporate under a watch glass.
Fraction 6: A point more aromatic than fraction 7,8 like there is carryover from fraction 5. No obvious sweatiness. Detectable gustatory acidity.
Fraction 7: Fairly neutral. No obvious sweatiness. Detectable gustatory acidity.
Fraction 8: Fairly neutral. No obvious sweatiness. Detectable gustatory acidity.
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