A poolish is a pre-ferment originating from Polish bakers (hence the name), widely used in French baking. It's a mixture of equal parts flour and water (100% hydration) with a small amount of yeast, fermented for 4-16 hours before mixing into the final dough. It adds flavour, extensibility, and a more open crumb.

How much of the flour should go into the poolish?

Typically 30-50% of the total flour weight. Using more poolish (50%) gives a stronger flavour contribution and more open crumb. Using less (30%) gives a more subtle effect. For baguettes, 33-50% is common.

How do I know when the poolish is ready?

A ripe poolish will have doubled or tripled in size, have a domed or slightly concave surface covered in bubbles, and smell pleasantly yeasty and slightly tangy. If it has collapsed significantly and smells very sour, it's over-fermented.

Why does yeast amount change with fermentation time?

Longer fermentation times need less yeast because the small amount has more time to multiply and ferment. Too much yeast for a long ferment means the poolish over-ferments, becoming too acidic and losing its lift.

How long should a poolish ferment?

A poolish should ferment at room temperature for 8-16 hours until it is bubbly, domed, and just starting to collapse. Shorter fermentation (8 hours) works if your kitchen is warm (24 degrees C+). Longer fermentation (12-16 hours) in a cooler kitchen (18-20 degrees C) develops more complex flavour.

BakeCalcs

Poolish Calculator

Calculate flour, water, and yeast for a poolish pre-ferment based on total dough weight.

Total Flour in Recipe

Total Water in Recipe (optional)

Enter to see adjusted remaining water

Poolish Percentage

Fermentation Time

How We Calculate This

A poolish is a 100% hydration pre-ferment — equal weights of flour and water with a tiny amount of yeast. The yeast quantity depends on how long you plan to ferment it.

The Calculation

Poolish flour = Total flour × poolish percentage (30-50%)
Poolish water = Poolish flour (100% hydration, equal weights)
Poolish yeast = Varies by fermentation time
Remaining flour = Total flour − Poolish flour
Remaining water = Total water − Poolish water

Yeast Guide (instant, per kg poolish flour)

4 hours: ~2.4g per kg flour
8 hours: ~0.8g per kg flour
12 hours (overnight): ~0.3g per kg flour
16 hours: ~0.1g per kg flour

Frequently Asked Questions

Related Calculators

Dough Hydration Calculator

Calculate the hydration percentage of bread dough from flour and water weights.

Yeast Conversion Calculator

Convert between fresh yeast, active dry yeast, and instant yeast quantities.

Sourdough Starter Calculator

Calculate flour and water needed to feed your sourdough starter to a target weight.

Sourdough Recipe Converter

Convert a yeasted bread recipe to sourdough, adjusting flour and water for starter hydration.

Desired Dough Temperature Calculator

Calculate the water temperature needed to achieve your target dough temperature.

Last updated: February 2026

All calculations are based on standard ratios and conversions. Results may vary with specific ingredients, equipment, and conditions.