Understanding alcohol yield in distillation is central to understanding spirit production. Yeast feed on sugar to produce ethanol, while the remaining liquid contains water as well as various chemicals including acids, aldehydes, esters and congeners – these components give spirits their flavour – both good and bad! Distillers must balance keeping these elements but only in adequate amounts for desired results.

Distillation is used to separate flavor components from water and ethanol by boiling off water through repeated cycles of vaporisation and condensation, with each cycle increasing alcohol concentration while decreasing congener content (see the graphic below).

At first, the lowest boiling-point compounds will be released – these are known as “heads” or ‘foreshots”, and their foul odour and taste isn’t ideal; further down comes more desirable ethanol alcohol vapors that have more desirable qualities which have become known as the ‘heart” of the run; by diverting their path out of the condenser they can be easily separated out and saved for future use.

Distillers aim for an end product that contains a high concentration of ethanol and lower concentrations of other congeners – and that’s exactly why we must understand % Yield. To calculate it, first know your Experimental Value; divide this figure by your Theoretical Value; multiply this resultant figure by 100; then this result will become your %Yield value.

How to Optimize Copper Contact in Distillation

Amidst the bustle and chatter of Chiaradia’s bustling workshop lies an old copper alambic that hasn’t been working in some time and requires attention before its next distillation season commences.

Copper has an affinity for sulfur, and enjoys binding it up into copper sulfides for later removal during distillation. Too much sulfur, however, may produce mercaptans with an unpleasant rotten vegetable aroma – not ideal!

As such, it’s imperative that spirits contain minimal amounts of sulfur. This can be accomplished by optimizing several factors, including length of vapor path (the number of condensation/re-volatilisation cycles that take place prior to distillation product leaving your still) and condenser temperature.

One easy way to reduce sulfur is to use copper alloy inner surfaces in stills and condensers, where native copper absorbs unwanted sulphur compounds to lower levels of dimethyl trisulfide (DMTS) produced from fermenting methionine during fermentation; on the other hand, corrosion promotes its formation.

As stainless steel remains the go-to material for distillation, copper remains an indispensable element in its distillation process. Copper can be added to a stainless steel still as part of its vapor path to enhance its ability to offload sulfides and induce desirable esterification reactions. Central Wire Industries Tech-Mesh provides this option and is an excellent way for distillers looking to integrate copper into their equipment.

Distillation Methods for Craft Spirit Production

When people think of spirits, most commonly they envision vodka, rum, whiskey and liqueurs. But what sets these beverages apart from beers or wines fermented with yeast (nondistilled alcohols)? Distillation.

Spirit distilling involves extracting alcohol from water through evaporation and condensation – a crucial step that sets spirits apart from non-distilled drinks like beer and wine. When distilling spirits, undesirable vapors known as “heads” often evaporate first – these include lethal amounts of methanol alcohol along with volatile compounds that disrupt flavor profiles. Disstillers typically discard these heads before running the liquid through another distillation called “heart,” which captures most of its desirable flavors.

At this stage, the distillate has reached approximately 80% to 90% alcohol content and requires additional distillations steps in order to reach its desired proof level.

Once their product has been made, many distillers choose to age it further before bottling and selling it. At this stage of distilling production lies the real art of craft distilling: this is when important decisions about aging should be made; including how long, type of barrel/bottle to use etc. However, unlike in beer or wine production there are no set regulations as such on what defines an “artisanal spirits producer,” so most will make independent choices regarding aging to achieve desired results.