This is one of the questions we often get from our Whiskey Still customers: how much alcohol can I expect my copper whiskey still to yield? It is, of course, very difficult to offer an exact answer. Quantity depends on a number of factors: ingredients, amount of sugar, type of yeast or final proof. A generic rule is that you will get about 10-20% of a still’s capacity: a 5 gallon whiskey still could potentially yield 1 gallon of moonshine, while a 10 gallon copper still, 2 gallons of alcohol.
Before hitting the copper whiskey still, the amount of alcohol present in your starting wash can impact the final yield, as you can obtain more from a stronger wash. This is influenced by two main factors: the amount of sugar present in the mash and the type of yeast you choose to use. You will generally add different amounts of sugar, depending on recipe and personal preference, but what is important is that there is enough sugar for yeast to turn into alcohol. Whether you obtain it through fermentation or add it yourself, sugar is essential for a strong starting alcohol, which, as I already said, is important for a good yield. This doesn’t mean you should overdo it on the sugar, just that correctly following a good recipe is always a good idea. For 10 lb of sugar, you should be able to get somewhere between 1.5 - 2 gallons of pure ethanol.
The type of yeast you choose is also very important. Bakers yeast can produce around 10% alcohol, while stronger distillers yeast or “turbos” can take it up to about 20%. But choose your yeast carefully, also considering other factors, such as your fermenting conditions, ingredients or distillate you want to obtain. Good yeast will help you get a higher final yield thanks to having generated a higher starting alcohol.
I also mentioned final proof among the relevant factors on which alcohol yield is dependant because strength is directly related to quantity. Only about half of the final spirit leaving your copper whiskey still will be pure alcohol though so your yield is actually double than the ethanol you calculate depending on your sugar input.
And, of course, cutting might play a part as only experienced distillers will make the most of their distillate and collect just the right amount of tasty shine, not too much to have an off taste but not too little to waste any of the good stuff either.
Posted by Jason Stone on