Distillation Run Time Calculator

Known rate mode is a straightforward division: the volume you plan to collect divided by your take-off rate. This is the more accurate mode if you have run your still before and know roughly how fast it collects.

Estimate from power mode works backward from thermodynamics. Vaporizing a liquid requires energy equal to its latent heat of vaporization. Ethanol vaporizes with far less energy than water, so a higher-ABV vapor stream can be produced faster for the same power input.

This calculator estimates run time only, starting from when distillate begins collecting. It does not include the time spent heating the still up to that point. Use the Heat-Up Time Calculator for that stage.

The take-off rate this calculator estimates is a snapshot at your stated vapor ABV, not a constant for the whole run. As the boiler's alcohol content depletes through hearts into tails, the vapor coming off becomes progressively weaker, closer to pure water. Since water requires far more energy to vaporize than ethanol, the achievable rate for the same power input drops as the run progresses.

In practice this means the early hearts collect faster than the late tails, even with the valve held at a fixed opening. Most distillers compensate by throttling down gradually as the run advances, or by accepting the natural slowdown and using it as one more signal that the tails cutoff is approaching.

A realistic distilling day budget has three stages: heat-up, the collection run itself, and pack-down. For a typical home stripping-and-spirit-run sequence, budget roughly 40–60 minutes for heat-up per run, the collection time this calculator estimates, and 20–30 minutes at the end for cleanup and cooling before you can safely move or store the still.

If you're running back-to-back batches in a single session, the second run's heat-up is often faster since the still and surrounding area are already warm, though this calculator's estimate assumes a cold start for the most conservative planning figure.