Cuts Calculator
Enter your still charge details to estimate fractions
Still Thermometer: A probe thermometer in the vapour path gives the most accurate cut timing readings.As an Amazon Associate we earn from qualifying purchases.
View on Amazon →Understanding the Four Fractions
Foreshots — The very first liquid off the still. Contains acetaldehyde, ethyl acetate, and other highly volatile compounds with boiling points lower than ethanol that concentrate in this fraction. Always discard, never taste. Volume is small — roughly 50mL per 20 litres of wash. Do not pour foreshots down the drain; they are flammable and make an effective cleaning agent or fire-lighter when kept in a clearly labelled waste container.
Heads — Come over after foreshots, still contain elevated levels of acetaldehyde and ethyl acetate. Smell sharp, fruity, and solvent-like. Can be redistilled or discarded. For a pot still spirit run this is roughly the first 10–15% of usable distillate.
Hearts — The main drinkable fraction. Smells clean, smooth, and characteristic of your spirit type. This is what you keep. For a pot still, hearts typically run from around 75–65% ABV down to around 58–55% ABV, depending on the spirit style.
Tails — After hearts. Contains fusel alcohols, which give a hot, oily, or "wet dog" character. Some distillers collect tails separately to add back in small amounts for character, or to redistill. Collection stops around 20–25% ABV.
Plan your run jar by jar before you start — know exactly which jar each cut happens in.
Wash Run vs Spirit Run
Wash Run (Stripping Run) — Running the fermented wash through the still to produce low wines or a stripped spirit, typically collected down to around 20% ABV. Speed matters more than precision here — cuts are minimal. Discard foreshots, collect everything else as low wines for the spirit run.
Spirit Run — Running low wines through the still a second time to produce the final spirit. This is where precise cuts matter most. The spirit run produces a more concentrated output and gives you better control over the heads/hearts/tails separation. Always collect in small jars and make final cut decisions by sensory evaluation after the run.
In-depth guide to heads, hearts and tails — sensory evaluation, cut ABVs by spirit type, and common mistakes.
Whisky Tasting Journal: Track every run — cuts, yield, ABV and tasting notes in one place. 100 structured entries, score /100, buy-again rating. 6 x 9 in, 116 pages, cream paper.