Pre-ferment Calculator

Poolish is a liquid pre-ferment at 100% hydration (equal flour and water). Biga is a stiff pre-ferment, typically 50–60% hydration. Levain is built from an existing sourdough starter instead of commercial yeast, so it carries wild yeast and bacteria rather than a measured yeast dose.

Most recipes put 20–40% of total flour into the pre-ferment; the calculator defaults to 30%. A larger share builds more pre-ferment flavor and shortens the final dough's fermentation, since more of the flour has already had a head start.

Poolish and biga are typically mixed and fermented 12–16 hours at room temperature before use. A levain's timing depends on your starter's own feeding schedule and how active it is, so judge it by rise and dome rather than the clock.

A small commercial yeast dose (about 0.25% of the pre-ferment's flour) gets the poolish or biga going reliably overnight. A much smaller supplemental dose (about 0.05% of the remaining flour) goes into the final dough as insurance, without overpowering the slow-fermentation flavor the pre-ferment builds.

No. A levain is built entirely from an active sourdough starter, so it supplies its own leavening. The calculator omits the yeast fields when you select levain, since a mother culture is already doing that job.

Salt is calculated on total flour weight across the whole recipe but added entirely to the final dough, never the pre-ferment. Salt slows fermentation, so keeping it out of the poolish, biga, or levain lets that stage develop at full speed.

Yes. The calculator defaults to 100% for poolish, 55% for biga, and 80% for levain, but you can adjust anywhere from 50–125% if you want a stiffer or wetter build than the standard version.