Bread & Dough poolish

Preferment Calculator

What is a poolish? A wet preferment of equal flour and water with a pinch of yeast, left 12 to 16 hours.

Add flavor to any bread with a preferment. Enter your flour, hydration and how much of the flour goes into the poolish, biga or levain, and get both mixes.

How to use it

  1. Enter the recipe's total flour and its hydration.
  2. Pick the preferment and the share of flour in it.
  3. Mix the preferment the night before, then the final dough.

How it works

The preferment takes its share of the flour and water; the final dough gets the rest, so the bread keeps the same overall hydration.

Poolish is made with equal flour and water; a biga is stiffer, about 50 to 60% water. These hydrations and the times are bakery convention and a starting point.

A levain is built from your sourdough starter at the hydration you choose.

Assumptions and limits

  • Weights in grams.
  • Room temperature around 70°F (21°C).
  • Instant yeast for poolish and biga.

Sources reviewed October 23, 2026.

Tips

  • A preferment is ready when it's domed and bubbly and just starting to sink.
  • Cut the final dough's yeast when using a preferment.
  • Cold kitchens slow preferments; give them longer.

Recipes to try it with

Questions

What is a poolish?

A wet preferment of equal flour and water with a pinch of yeast, left 12 to 16 hours.

What's the difference between a poolish and a biga?

A biga is stiffer, with about half as much water as flour.

How much of the flour should go in the preferment?

20 to 40% is common; 30% is a good start.