A major feature of the birectifier is its ability to teach sensory skills and intuition to new distillers by analyzing role models and playing with the output. Each birectifier fraction (collected in the traditional way) can be seen as a 10 x concentrated facet of a spirit. That number is arrived at because each 25 ml fraction collected an extremely high reflux is typically from 250 ml of 40% ABV spirit. We can use this fact to micro-vat, via pipette, small scale abstracted versions of spirits to see what they would look like if a feature was enhanced and blown out.
Setting this up and experiencing it can be a great project for a new distiller or apprentice. When we do this, not all of the birectifier fractions are used. I only use 1, 4, 5, and 6. The other unused fractions can be seen as alignment fractions, or perhaps only answer questions we do not want to ask at the moment (distillation flaws appear in the last three fractions).
Adding only Fraction 1 gives a glimpse of a spirit with more low boiling point, low molecular weight congeners like ethyl acetate and acetaldehyde.
Adding only Fraction 4 gives a glimpse of a spirit with more fusel oil because 75% of the fusel oil lies in this fraction.
Adding only fraction 5 increases the quality regulating fraction.
Adding only fraction 6 would increase long chain fatty acids and other long chain congeners that are too high boiling point or too high molecular weight to make it into the quality regulating fraction.
In the above example, I started with four nosing glasses with 12.5 ml of spirit to be tested. In this case it was an exemplary Bourbon. I added 1.25 ml of each fraction to somewhat double the congeners of each category and let it sit for two hours to integrate. I say somewhat because not 100% of a given congener category lives in a single fraction, but we know there are fractions where the vast majority live and that is good enough for a sensory sketch.
An apprentice could slowly elaborate each congener category sideways to look at progressively varying ratios of abstraction:
12.5 ml of finished commercial spirit to be explored.
1.25 ml 100% increase of a congener
0.94 ml 75%
0.63 ml 50%
0.31 ml 25%
0.13 ml 10%
What does it feel like when a spirit is asked to absorb more of a certain congener category? Well, the answer is interesting. The spirit does not immediately turn into a monster, even when you double things, because other facets still compete for attention. That’s the big takeaway. It is an attention game.
Because we are typically working with a role model, we assume that a studied spirit has what it has because a large and experienced producer systematically explored all their options. They went left, they right, they know exactly why they are where they are. If this test were performed on a new spirits production, more congeners, for example, may be better and a plan for action would be supported. Further tests may be called for, but the inquiry may start with the quick sensory sketch. New producers are more likely to be conservative on cutting rather than overzealous (they cut too much and distill at too high proofs).
One pitfall to our inquiries is that we may enjoy an abstracted expression just because of the novelty, and not admit to ourselves that it is a flaw or not optimal. This happens a lot in the natural wine making community. So many flaws have been eradicated by the industry that when they turn up, they are often mistaken for features and possibly an expression of terroir. They are ordinary in textbook theory, but somehow have a low frequency of occurrence in terms of what is presented on the market. Sensory flaws do not truly become flaws until they get attached to symbolic concepts like regrets or missed opportunities.
These sketches are much harder to taste and compare to the unameliorated control than you’d think because of the cacophony of surrounding congeners. This is the beauty of the isolated birectifier fractions. They are collected in a standardized enough way to make comparisons, and in their isolation from the surrounding noise, become far easier to interpret. All the sensory noise means that we may not be able to take in all the sensory sketches in one go. It may be necessary to pause, take a break, and return frequently.
Typically, birectifier fractions are diluted for organoleptic analysis, but we are purposely not diluting anything in this sensory sketches because we are trying to experience the product like an end consumer would. An inquisitive apprentice would no doubt benefit from also tasting the range at various dilutions.
All of these congeners will have a relationship to the terroir concept. Some are ordinary, the byproduct of basic yeast metabolism, and inhabit all spirits, while some are extraordinary, begin to define a spirit, or are site specific. Distillers to some degree aim to reduce surplus ordinary congeners from overshadowing and obscuring the extraordinary (frequency of occurrence rules everything around us). That is not the whole story because they also need to acknowledge the supporting role these congeners play in filling sensory space and walk the line of maximizing their contribution. This happens not just during still operation, but at every juncture of production.
Short sensory sketches with the birectifier can teach us a lot. The experience gained will help us understand the decisions of our role models better so we can mimic them and play along. Spirits are brought together into categories, not just by their substrates, but by ordinary congeners and their ratios. Spirits differentiate themselves by their content of the hard won, divine, extraordinary (fraction 5!). Don’t forget, the more tests we develop to hone our skills, the more we will develop educated distillers who we can delegate tasks to. You can do a lot with a birectifier. Sensory Sketch!
Fraction 1: Nosing did not reveal anything clearly out of whack but tasting was apparent. A headiness was distracting from other more nuanced components.
Fraction 4: Again nothing was too apparent just by nosing, but an out of the ordinary acridness was readily apparent upon tasting.
Fraction 5: Nosing detected an attractive intensity, but something seemed slightly amiss on the palate. We think of fraction 5 as where the personality of a spirit and the divine lies, but as it is increased, other facets may have to also grow to provide tension and keep the spirit from feeling fat. It is hard to say what exactly those other facets are at the moment. Alcohol could easily be one of them.
Fraction 6: I intend my metaphors here to be very imprecise, but I detected a very generic creaminess in the spirit by increasing this fraction. Others note an oiliness in certain spirits and we may be pointing at the same thing.