How To Moonshine

Fermenting &
Distilling Basics
Making Equipment
How to Make Moonshine Using Sugar How to Make Moonshine Using Grain Moonshine Recipes

Distilling Moonshine

Distilling moonshine requires a still (of course!) but many people are unclear as to how a still works and what it actually does for the spirits you are making. There are different kinds of stills as well just to make things less clear and each type of still is more suitable to particular tasks than others. This web sites article on different types of stills does briefly touch on the main types of stills commonly used in industry and home distillation alike however for the most part we shall focus on pot stills, how they work and their different uses.

First lets rewind a little and take a quick look at how distillation works in general. Lets assume you have made a basic sugar wash and are now looking forward to distilling it in a pot still such as my still pictured on the bottom left of this page. The image on the top left of this page is a simplified drawing I have made of my still that shows how it works. The wash (grey) is poured into the still (black) and heated by a 2000w electric element (red). As the wash heats and boils the vapours and steam (lightest blue) rise up into the condenser (medium blue) which turns the vapours back into liquid form (darkest blue) which is essentially the stills output, your spirit.

When you make a wash it will contain a number of different substances all mixed in together, there will be water, alcohol (ethanol), some byproducts of fermentation such as methanol and other components that can be used to contribute to the flavour of the finished product if desired. Of course the alcohol (ethanol) is the main thing that we want, there are also some parts of the wash we want to remove as completely as possible such as the methanol which will cause hangovers in small quantities and send you blind in large quantities. There are congeners that should be kept if you are making a flavoured spirit or ommitted if you are making a neutral spirit.

A still provides the means to seperate these different substances from the wash based on their boiling points. For example the undesirable methanol boils at 64°C while ethanol boils at 78°C and they are both contained in a wash which is mostly water which boils at 100°C. When these substances are combine together and heated the boiling point of the entire liquid is reduced and the substances with the lowest boiling point will tend to turn to vapour first. So the methanol will turn into vapour first, rise into the condenser and be returned to liquid form. It will exit the condenser to be collected and discarded. Unfortunately, there will always be some degree of overlap between the different substances so in practice when the vapour temperature climbs you will initially collect mostly methanol and it will change from being mostly methanol to being a mixture of ethanol and methanol until no more methanol is present. At this point the vapour temperature will be around 78-82°C and the still output will be mostly ethanol.

This overlap is very pronounced in pot stills and is both an asset and a liability of their design. If I run a sugar wash that has fermented to 20% alcohol through my still once (removing the first 200mls to get rid of the methanol of course) the resulting output will be about 60-65% alcohol. If I then run this through my pot still again it will jump up to the low 90's and a third pass will bring it to just over 95%, which is as pure as it can possibly be (and pretty deadly, dont drink it at that strength). A reflux or a fractionating still will be able to produce this in one pass, perfect for those who are producing a base spirit as it will contain virtually no flavour and be perfect to water back to whatever strength you prefer (40-65%) and flavoured using spirit essences.

On the other hand this overlap can be useful when making flavoured spirits such as whisky or bourbon. As the vapour temperature increases above 78-84°C the output of the still starts to change to a mixture of ethanol and other substances called congeners that are byproducts of the fermentation process. These substances include small amounts of chemicals such as acetone, acetaldehyde, and other higher alcohols, esters, and aldehydes (e.g. propanol, glycols, ethyl acetate). Congeners are a big contributer to the taste and aroma of flavoured spirits and are the majority of the stills output by the time the vapour temperature exceeds 90°C or so. Controlling the amount of congeners in your spirit is much easier when using a pot still rather than attempting to detune other types of stills and is as easy as ceasing to collect the stills output when the vapour temperature reaches a certain point. It is quite common to collect the stills output in seperate vessels, hence seperating the pure ethanol from the congeners and varying mixtures of both in between so you can blend the final product based on your personal tastes and run what remains through the still again with your next batch to increase yield. This process of seperating the output of the still from different stages is called making cuts.

Once the vapour temperature reaches 92-94°C you will notice that the output of the still has turned milky and has an unpleasant odour. The substances you will seperate from the mash at this temperature are called fusel alcohols or fusel oils and they can contribute to off flavours in your spirit. In general most of these are not collected, most moonshiners shut their still off when the vapour temperature reaches 92°C.