How to Make a Poolish: Recipe, Ratio, and Timing

A poolish is a loose yeasted pre-ferment, conventionally made with equal weights of flour and water and no salt. You ferment it before mixing the final dough. It needs no maintained sourdough culture, and its visible bubbles make it a useful introduction to preferment baking.

The pre-ferment overview compares poolish with biga, old dough and levain. Here, the focus is mixing, observing ripeness and counting the build correctly in a bread formula.

The Poolish Formula

The defining calculation is water weight divided by flour weight: equal weights give 100% hydration.

For the example build:

• 250g bread flour
• 250g water
• 0.25g instant yeast, equivalent to 0.1% of the poolish flour

The tiny yeast quantity must be measured reliably. A standard scale displaying whole grams cannot directly measure a quarter gram. Use a scale capable of measuring that amount accurately, or follow a published recipe that specifies a small spoon measure. Do not assume every pinch is 0.25 g.

This dose is a starting example for an overnight schedule. The flour-water ratio and yeast percentage do different jobs: the former defines hydration; the latter helps determine how quickly the build develops at a given temperature.

A conventional poolish omits salt. That is its usual formulation, not a claim that yeast cannot ferment salted dough. Other preferments, such as pâte fermentée, contain salt.

How to Mix It

Combine the ingredients and stir until all flour is moistened. It usually takes only a short stir; do not stop at an exact 30 seconds if dry patches remain. Instant yeast can be mixed with flour, so separately dissolving it is optional unless its manufacturer directs otherwise.

Use a clean food-safe container with plenty of headroom. Cover it to limit evaporation. A loosely fitted lid or a covered bowl works; a vented fermentation container is another option. Avoid an airtight, pressure-building ordinary glass jar. There is no need to leave the batter exposed or make a drying draft through its cover.

Mark the starting level if the container allows it. That gives you a clearer record of expansion and any later recession.

What Poolish Can Change

Flavor: A pre-ferment changes the fermentation schedule and can add aromas you enjoy. Shorter straight doughs also produce fermentation compounds, so the difference is not their complete presence or absence. Nor is more complex flavor everyone’s preference: King Arthur baker Martin Philip describes his preference for a direct-method baguette. Compare breads and decide what you like.

Handling and crumb: Poolish can increase extensibility, making dough easier to stretch. Final gluten development, hydration, bulk fermentation and shaping still determine how the loaf holds gas. A poolish does not guarantee large holes, and excessive maturation can make handling worse.

Keeping quality: Prefermentation may improve some aspects of freshness, but it does not give bread a fixed four-to-five-day life. Mold resistance and staling are different issues. Formula, baking and storage all matter; freeze bread you will not use promptly. Discard moldy bread, including prefermented bread.

Where and When to Ferment

For this example, a stable room around 68–72°F is a reasonable starting environment, with roughly 12–16 hours allowed. As a point of comparison, King Arthur’s baguette workbook gives its own poolish about 15 hours at 68–72°F. Use the quantity and yeast dose from whichever complete recipe you choose.

A 12-hour schedule could run from 8PM to 8AM; a 16-hour schedule from 8PM to noon. These are planning examples, not readiness deadlines.

Warmer conditions usually bring maturity sooner, while cooler conditions slow it. There is no dependable rule that every kitchen below 65°F needs exactly 18–20 hours, or every one above 75°F needs 8–10. Check the actual build and record when it matures. Adjust one variable in the next batch rather than changing yeast, temperature and timing simultaneously.

How to Tell When a Poolish Is Ready

Look for substantial expansion and an active, bubbly surface. Aroma may be pleasantly yeasty, but smell is not a precise maturity measurement. A surface starting to recede can be useful context; a pronounced collapse and a high-water mark indicate that the build has already risen and fallen.

In Hamelman’s published preferment discussion, poolish readiness is described through surface bubbles and activity. His domed-and-receding description there is for stiff biga and pâte fermentée. Different consistencies need not form the same dome.

Do not equate 16 hours with a switch from ripe to unusable. Likewise, a little alcohol aroma is a normal consequence of yeast fermentation; it does not prove that all sugars are exhausted. An old, greatly collapsed build may perform differently enough that starting again is the more predictable choice, but an exact number of hours past peak cannot diagnose that on its own.

If You Need to Delay

A slightly late but otherwise sound poolish may still be usable, with possible changes in flavor and dough behavior. It cannot promise the same result as a build used at the intended stage.

Refrigeration slows fermentation and may help with a planned delay. How useful it is depends on maturity before chilling, cooling rate and refrigerator temperature. It does not restore a spent build, and there is no universal extra 24-hour allowance.

When mixing with a cold poolish, account for its temperature in the final dough. Do not automatically warm it for another two hours solely to “reactivate” yeast: fermentation and temperature adjustment should fit the recipe. Discard a build with mold, unusual colored growth or suspected contamination; baking is not a way to rescue such a build.

Poolish vs. Other Pre-ferments

For liquid and stiff sourdough builds too, see the pre-ferments guide.

Three Worked Formula Examples

The following quantities illustrate how poolish fits into different doughs. They are formula-development examples, not bake-validated recipes; loaf size, flour performance and complete proofing/baking schedules need validation before relying on them for a finished result. For a complete published baguette recipe, use King Arthur’s Classic Baguettes.

1. Poolish Baguette Example

Poolish:

• 500g bread flour
• 500g water
• 0.5g instant yeast

Final mix:

• All the poolish
• 500g bread flour
• 20g salt
• 3g instant yeast
• 150–180g water

This contains 1,000g total flour, 50% prefermented flour and 65–68% total hydration. Only the upper water quantity gives 68%. Total salt is 2%; total instant yeast is 0.35% of all flour.

Mixing the poolish with flour and water before adding salt is a preferment-containing rest, not the flour-and-water-only version of an autolyse. Final mixing should develop adequate strength, followed by bulk fermentation, division, shaping and proofing judged from the dough. Exact times need testing with the chosen yeast, flour and temperatures.

The baguette guide covers shaping. For baking, match baguette size to the method and use an oven-appropriate steam setup; a single baking time cannot cover every division of this batch.

2. Poolish Pizza Example

Poolish:

• 250g bread flour or a suitable pizza flour labeled “00”
• 250g water
• 0.25g instant yeast

Final mix:

• All the poolish
• 250g flour
• 10g salt
• 2g instant yeast
• 25–50g water
• 10g olive oil, optional

This has 500g total flour, 50% PFF and 55–60% water hydration. Oil is a separate ingredient, not water. Without oil, dough mass is approximately 787–812g; with it, approximately 797–822 g. Three equal balls would therefore be about 262–271g without oil or 266–274g with oil, before handling losses.

“00” does not specify one protein level or water absorption. Use a flour suitable for the recipe. Proof until the balls are ready to stretch rather than assuming a poolish guarantees a puffy rim. Choose a baking schedule suitable for your steel or stone, oven and toppings, within equipment temperature limits.

3. Poolish Sandwich-Bread Example

Poolish:

• 200g bread flour
• 200g water
• 0.2g instant yeast

Final mix:

• All the poolish
• 300g bread flour
• 10g salt
• 4g instant yeast
• 30g sugar
• 30g softened butter
• 50–80g milk or water

This has 500g total flour and 40% PFF. With water, added water is 50–56% of flour; with milk, the same quantity is added liquid, not an equal amount of water. Butter also contributes some water. The relatively firm formula needs evaluation with the selected flour; do not assume the whole liquid range gives identical handling.

Use the mixer’s manufacturer-approved bread-dough speed and capacity. Assess development and proofing from the dough. Pan size, dough quantity and desired loaf shape must fit one another, so a fixed height above a pan rim is not enough to validate the method. A complete bake trial is still needed for this example, including crumb quality after cooling and the appropriate baking schedule.

Count Prefermented Flour Correctly

PFF means flour in the poolish divided by total flour, not poolish weight divided by flour. A 200g flour-and-water poolish contains 100g flour. In a dough with 500g total flour, that is 20% PFF, although the whole poolish weighs 40% of the flour weight.

There is no mandatory 30–50% band. For example, the current Classic Baguettes formula puts 120g of its 540g flour in the build, about 22.2%. Its build uses 113g water, illustrating that some published recipes use “poolish” for a mixture close to, rather than exactly at,100% hydration. Follow the actual quantities when using that recipe.

Adding more ripe poolish changes flour fermentation, water distribution and inoculation together. It does not guarantee more open crumb or a fixed reduction in proofing time. Keep a complete formula and avoid counting the same flour and water twice.

For yeast substitutions, see Red Star’s product instructions. The published measurements of ethanol in ordinary foods also show why baking should not be described as guaranteeing zero residual alcohol in bread.