Spirit Distillation Cut Calculator (Heads, Hearts, Tails)

Fractional distillation is a separation process that relies on boiling points to isolate ethanol from other compounds. A critical safety aspect for home distillers is the removal of the "Foreshots" and "Heads," which contain methanol and acetone. Consuming these can lead to blindness or severe toxicity. Accurate volume estimation allows the distiller to prepare collection vessels and anticipate the yield of the "Hearts" cut, which contains the desirable ethanol.

This calculator estimates the volume of each fraction based on the total volume of the wash and its alcohol concentration. The ratios provided are based on standard pot still runs for spirits like whiskey or brandy. It assumes a typical distribution where Foreshots represent the first volatile compounds, followed by the Heads (solvent-like notes), the Hearts (clean spirit), and finally the Tails (fusel oils and wet dog aromas).

The calculation first determines the volume of pure alcohol in the wash:

Each cut is then estimated as a percentage of this pure alcohol volume. Note that the collected liquid volume will be higher than the pure alcohol volume because the distillate is never 100% alcohol (usually coming off the still at 60-80% ABV). The calculator provides the Target Collection Volume assuming an average still output.