Work out distillation cut yield instantly with clear inputs, formula shown and shareable results.
Total pure alcohol in the wash is volume times ABV. The hearts cut captures 55-75% of that, with foreshots, heads and tails discarded or recycled. Dividing the hearts alcohol by the collection strength gives the volume actually collected, and dividing by 0.28 litres of alcohol gives 700 mL bottles at 40%.
Pure alcohol
Litres of pure alcohol = wash volume x ABV
Hearts
Hearts volume = pure alcohol x hearts fraction / collection ABV
Distillation of spirits requires a licence in nearly all jurisdictions and improperly made spirit can contain toxic levels of methanol. Alcohol vapour is also highly flammable.
They concentrate methanol, acetaldehyde and ethyl acetate, which are toxic and unpleasant. Foreshots must always be discarded, not recycled into a drinkable product.
By nosing and tasting the distillate at intervals, supported by temperature and strength readings. Cut points are style decisions as much as safety ones, and are usually fixed by trial and kept constant.