CookBook Team

Poolish, biga and levain compared

Poolish, biga and levain are preferments: part of the flour and water mixed and fermented before the final dough. They differ in hydration and in whether commercial yeast or a sourdough culture does the work.

A sliced rustic loaf and pizza dough balls beside flour on a kitchen counter

CookBook TeamUpdated Oct 10, 2026

Poolish, biga and levain at a glance

All three move part of a recipe’s flour and water into a separate mix that ferments for hours before the final dough is made. The figures below are typical values from professional formulas, with percentages based on the preferment’s own flour.

Feature	Poolish	Biga	Levain
Hydration	100%: equal weights of flour and water	Usually 50–60%, a stiff dough	50–125%: liquid levains 100–125%, stiff ones about 60%
Leavening	Commercial yeast	Commercial yeast	Wild yeasts and lactic acid bacteria from a sourdough culture
Typical yeast	Depends on the recipe and yeast type; BAKERpedia uses up to 3% compressed yeast for a 1–2 hour poolish	About 0.1% instant or 0.8–1.5% fresh yeast	None added; seeded with ripe starter, for example 20% of the levain flour
Time and temperature	8–16 hours in a room at about 18–24 °C (65–75 °F)	8–16 hours at 15–20 °C (59–68 °F)	12–16 hours for a levain build; builds held at 23–27 °C (73–81 °F)
Effect on dough and bread	More extensible dough, nutty flavour, shorter mixing	Stronger dough, open crumb, aromatic flavour	Acidity that strengthens gluten, tang, longer keeping
Typical uses	Baguettes and other French breads	Ciabatta and other Italian breads	Sourdough breads, including rye

Sources: King Arthur Baking’s preferment reference and preferment guide, and BAKERpedia’s pages on poolish, biga and levain.

They do not agree on everything. BAKERpedia defines biga as stiff, while King Arthur points out that in Italy biga is a general word for a preferment and can be anything up to 100% hydration. King Arthur describes poolish as nutty and biga as floral and aromatic, but when Modernist Bread made preferments from 50% to 100% hydration and adjusted each final dough to the same overall hydration, the loaves looked nearly identical and the differences in taste were very subtle.

How to build each preferment

Poolish

Mix equal weights of flour and water with a pinch of yeast until smooth, cover and leave at room temperature. King Arthur’s professional formulas use 0.1–0.2% yeast on the poolish flour and ripen it for about 8 hours, or 14–16 hours on a one-shift schedule; a room at 18 °C (65 °F) needs more yeast than one at 24 °C (75 °F). BAKERpedia’s timing table, at a dough temperature of 26–29 °C (79–84 °F), runs from 0.25% compressed yeast for 12–15 hours to 3% for 1–2 hours. For a home batch, use 300 g flour and 300 g water, then follow a specific poolish recipe for the type and amount of yeast and its fermentation conditions. Instant, active dry and compressed yeast are not interchangeable gram for gram.

Biga

Mix flour with 50–60% of its weight in water and about 0.1% instant yeast (or 0.8–1.5% fresh) only until no dry flour remains; you are not trying to develop gluten yet. BAKERpedia ferments it for 8–16 hours at 15–20 °C (59–68 °F). King Arthur’s professional ciabatta uses a 60% biga with 0.1% yeast for about 16 hours, holding 30% of the total flour. A home-sized batch: 300 g flour, 180 g water and 0.3 g instant yeast.

Levain

A levain is built from a portion of ripe sourdough starter plus fresh flour and water. King Arthur’s professional sourdough baguettes use a liquid levain of 100 parts flour, 100 water and 20 ripe starter by weight, left 12–15 hours at room temperature; its Five Seed Sourdough uses a 125% levain for about 16 hours. BAKERpedia feeds its stiff levain at 60% water. Temperature shapes the acidity: BAKERpedia notes that 29–32 °C (84–90 °F) favours lactic acid, while lower temperatures favour acetic acid. A home-sized batch: 150 g flour, 150 g water and 30 g ripe starter.

Accounting for a preferment in baker’s percentages

Work from the overall formula. Decide the total flour, water and salt for the whole recipe, choose how much of the flour to preferment, then subtract the preferment’s flour and water from the totals to get the final dough. This is the layout the Bread Bakers Guild of America uses in its formula standard.

Prefermented flour (%) = flour in the preferment (g) ÷ total flour (g) × 100

Worked example: 1 kg flour at 70%, 30% prefermented

The overall formula is 1,000 g flour (100%), 700 g water (70%) and 20 g salt (2%). With 30% of the flour in a 100% poolish, the poolish holds 300 g flour and 300 g water. Yeast is omitted from this flour-and-water accounting example; use the type and quantity required by your recipe.

Ingredient	Overall formula	Poolish	Final dough
Flour	1,000 g (100%)	300 g	700 g
Water	700 g (70%)	300 g	400 g
Salt	20 g (2%)	0 g	20 g
Poolish	Counted as flour and water	600 g made	600 g, all of it

Hydration both ways: the final dough alone is 400 ÷ 700 × 100 = 57%, while the overall formula is 700 ÷ 1,000 × 100 = 70%.
Preferment as an ingredient: 600 ÷ 700 × 100 = 86% of the final-dough flour. A recipe written on the final-dough convention would list the poolish this way.
Swap in a 60% biga at the same 30%: the biga holds 300 g flour and 180 g water, so the final dough gets 700 g flour and 520 g water. Final-dough hydration rises to 74%, but the overall hydration is still 70%.
Yeast: add the final-dough yeast your recipe calls for. Because the preferment is already fermenting, the final dough usually needs a shorter bulk fermentation.

For more on why stated hydrations differ, see dough hydration explained. The baker’s percentage calculator splits a preferment into its flour and water and reports the prefermented flour for you.

Readiness cues

Poolish: risen, bubbly across the surface and pleasantly tangy. At its peak the surface starts to wrinkle and the volume begins to drop slightly. Left much longer, it breaks down gluten and builds too much acidity and alcohol.
Biga: domed, and just beginning to recede in the centre.
Levain: doubled or tripled in volume, foamy, pleasant smelling and just starting to sag in the middle. A fed starter often reaches this point 6–8 hours after feeding. Do not rely on the float test: King Arthur found that starter can float before it is ripe, although a sample that sinks is definitely not ready.

Clock times in recipes assume a temperature. If your kitchen is cooler or warmer than the recipe’s, watch the preferment rather than the timer.

Which one should you use?

Poolish if you want an extensible dough for baguettes or other lean breads and can mix it the evening before. Its batter-like texture blends easily into the final dough.
Biga if you are making ciabatta or another wet Italian bread and want extra strength and an open crumb, or your kitchen runs cool.
Levain if you want sourdough flavour, acidity and keeping quality without commercial yeast, and you already keep an active starter.
No separate preferment for Neapolitan pizza made to AVPN rules, which describe a direct dough. They do allow natural sourdough at under 10% of the flour. Work out the dough in the pizza dough calculator.

If you cannot decide between poolish and biga, choose by schedule and handling. Modernist Bread’s comparison suggests that once the overall hydration matches, the finished loaves differ very little, and its authors prefer a 100% poolish because stiff preferments are harder to mix in evenly.

Keep your formulas together in CookBook

CookBook saves bread and pizza recipes from websites, social posts, photos and cookbooks, and keeps them organised in one place. In cooking mode you can change servings and switch measurement systems: ingredient amounts scale, but times in the method do not, so keep reading the preferment, not the clock.

Sources

A little more help

Frequently asked questions

Is a levain the same as a sourdough starter?

Not quite. The starter is the culture you keep and feed indefinitely. A levain is a batch built from a portion of it with fresh flour and water, sized for one bake. BAKERpedia notes that the two words are often used interchangeably in the United States but not in Europe.

Do I still add yeast to the final dough when I use a poolish or biga?

Usually, yes. King Arthur Baking’s professional French bread and ciabatta formulas add yeast to the final dough as well as to the preferment. Some levain breads also add a little, for example 0.2% of the flour in King Arthur’s sourdough baguettes.

Can I replace a poolish with a biga in a recipe?

Yes. Keep the same amount of flour in the preferment and move water between the preferment and the final dough so the overall hydration stays the same. A biga holds less water than a poolish, so the difference goes into the final dough. Modernist Bread found loaves made this way were nearly identical.

How much of the flour should go into the preferment?

Professional formulas often preferment about a quarter to a third of the total flour: 25% in King Arthur Baking’s Five Seed Sourdough, 30% in its ciabatta and 33% in its French bread with poolish. BAKERpedia measures by dough weight instead: its ciabatta uses biga for 40% of the final dough, and it says a poolish can make up as much as 60%.

Why is my preferment ready earlier or later than the recipe says?

Temperature and the amount of yeast or starter set the pace. In BAKERpedia’s poolish table the same 100% poolish takes 1–2 hours with 3% compressed yeast and 12–15 hours with 0.25%, and a cooler room slows everything down. Judge it by the readiness cues rather than the clock.

Still have a question? Visit our help centre.

Cite this page

Referencing these numbers or explanations? Copy this citation and link to the page.

“Poolish, biga and levain compared”, CookBook Manager. Updated Oct 10, 2026. https://cookbookmanager.com/guides/poolish-biga-levain

Text, tables and data on this page are available under the Creative Commons Attribution 4.0 licence (CC BY 4.0). Credit CookBook Manager and link to this page when you reuse them.