Still Run Yield Calculator (Foreshots, Heads, Hearts & Tails)

How it works

absolute alcohol = charge × ABV · recovered ≈ 85% (pot spirit run), 90% (reflux), 95% (stripping) · distillate volume = recovered ÷ average collection ABV (pot ≈ 60%, reflux ≈ 94%, stripping ≈ 30%) · fractions by % of recovered alcohol: heads ≈ 20–25%, hearts 50–65%, tails the rest; foreshots ≈ 2 mL per litre of wash · bottled = hearts LAA ÷ bottling ABV

Distillation does not create alcohol, it concentrates what the wash already holds, so the whole run is bounded by the litres of absolute alcohol charged and the fraction the still can recover before the output grows too weak to bother with. Different compounds boil off in a rough sequence — the volatile solvents first, then ethanol at its purest, then the heavy, oily congeners as the boiler runs dry — which is why the run is split into foreshots that are discarded, heads and tails that are saved to redistil, and the hearts that are kept. The proportions are set partly by the still (a reflux column separates far more sharply than a pot) and partly by the distiller's nose, so the percentages here are a map to plan volumes and jars around, not a rule.

Worked example

A 25 L wash at 12% holds 3.0 L of absolute alcohol. A pot-still spirit run recovers about 85% — 2.55 L — as roughly 4¼ L of distillate averaging 60%: about 50 mL of foreshots, 0.75 L of heads near 75%, 2.25 L of hearts at about 68% and 1.5 L of weak tails. Diluting the hearts with about 1.6 L of water gives 3.8 L at 40% — five 750 mL bottles — and the heads and tails hold another 1.0 L of alcohol for the next run.

Frequently asked questions