What's the difference between a poolish and a sourdough starter?

A poolish uses commercial yeast and ferments for 12-16 hours before being used entirely in one bake. A sourdough starter is an ongoing culture of wild yeast and lactic acid bacteria that you maintain indefinitely through regular feedings. Poolish produces a milder, sweeter flavor — nutty and complex without the tangy sourness that sourdough cultures generate. A poolish is also dead-simple to time: mix it the night before, use it the next morning. Sourdough starters require learning to read the culture's activity level, and the timing window varies with temperature, feeding ratio, and flour type.

Can I make a poolish with whole wheat flour instead of bread flour?

Yes, and it produces a nuttier, earthier flavor. Whole wheat flour ferments slightly faster than white flour because the bran contains more available sugars and minerals, so your poolish may be ready in 10-14 hours instead of 12-16. You may also notice a thinner, more batter-like consistency because whole wheat absorbs water differently — the bran soaks up moisture over time. One approach: use a 50/50 blend of whole wheat and bread flour in the poolish for some whole-grain flavor without the faster fermentation timing.

How much poolish should I use as a percentage of total flour?

Forkish recommends 30-50% of the total flour in the recipe, and Hamelman's poolish baguette uses 50% pre-fermented flour. Within that range, more poolish means more flavor complexity and a more open crumb, but also faster final fermentation (since a larger portion of the dough is already fermented). At 30% PFF, you get a noticeable improvement over straight dough with a generous final fermentation window. At 50% PFF, the flavor impact is more pronounced but you need to watch the final dough more carefully — it will be ready to shape and proof sooner.

My poolish smells like alcohol — is it still good?

A mild alcohol smell is normal and expected — yeast produces ethanol as a byproduct of fermentation, and some of it accumulates in the poolish. The ethanol evaporates during baking and does not affect the final bread flavor. However, a strong, sharp alcohol or nail-polish-remover smell means the poolish is significantly over-fermented. At that point, the yeast has exhausted most of the available sugars and the flavor contribution will be diminished. If the dome has fully collapsed and the smell is aggressively alcoholic, it's better to start a fresh one — it only takes 30 seconds to mix.

Can I use active dry yeast instead of instant yeast for a poolish?

Yes. Dissolve the active dry yeast in the water before adding flour — active dry yeast needs to hydrate in liquid before it begins working, unlike instant yeast which can be mixed directly into flour. Use about 25% more active dry yeast than the instant yeast amount in the formula, since active dry yeast has a lower percentage of viable cells. So if the recipe calls for 0.25g instant yeast, use about 0.3g active dry yeast dissolved in the water first.

Do I need a kitchen scale to make a poolish?

Strongly yes. At the quantities involved — 0.25g of yeast is about 1/16 teaspoon — volume measurements aren't reliable. A basic digital scale that reads to 0.1g is inexpensive and transforms accuracy. If you only have a scale that reads to 1g, pre-mix a larger batch of yeast (say, 10g yeast + 90g flour) and use 2.5g of that blend as your 0.25g yeast equivalent. For more on the equipment that makes bread baking accurate, see our [bread baking equipment guide](/blog/bread-baking-equipment-guide/).

Can I double or scale a poolish recipe?

Yes. A poolish scales linearly — keep the flour:water ratio at 1:1 and the yeast at 0.1% of flour weight, and the timing stays about the same. A 500g poolish ferments in roughly the same 12-16 hours as a 100g poolish because the yeast-to-flour ratio is what controls the fermentation rate, not the absolute quantity. Larger batches may take 30-60 minutes longer simply because the center of the mass is slightly insulated from ambient temperature swings.

How to Make a Poolish: The Easiest Pre-Ferment

A poolish is the simplest pre-ferment a baker can make. Equal parts flour and water, a tiny amount of yeast, no salt, no kneading, no special equipment. Mix it in a jar or container, leave it overnight, and the next day you have a bubbling, sweet-smelling batter that transforms the flavor and texture of any bread you add it to. If you want to understand how poolish fits into the broader world of pre-ferments (biga, pate fermentee, levain), see our pre-ferment overview. This article is the hands-on tutorial: how to mix one, when it’s ready, what to do if you miss the window, and three recipes that put it to work.

The Poolish Formula

A poolish is always the same ratio:

Flour: Any amount (typically 30-50% of the total flour in your final recipe)
Water: Equal weight to the flour (100% hydration)
Instant yeast: A tiny amount — about 0.1% of the flour weight
Salt: None. Salt inhibits the fermentation you’re trying to encourage.

Example batch: 250g bread flour + 250g water + 0.25g instant yeast (about 1/16 teaspoon). That’s it.

The yeast quantity is deliberately small. A quarter-gram of yeast in 250g of flour produces a long, slow fermentation — 12-16 hours at room temperature — that develops complex flavor compounds no short fermentation can match. More yeast would speed things up but produce a blander, less interesting pre-ferment.

How to Mix a Poolish

Stir the yeast into the water until dissolved. Add the flour. Stir with a spoon or spatula until no dry flour remains — about 30 seconds. The mixture should look like a thick, lumpy pancake batter. Don’t worry about smoothness; the overnight fermentation will hydrate everything fully.

Cover loosely. The container needs to breathe (CO2 must escape) but shouldn’t dry out. A lid set ajar, a plate, or plastic wrap with a few holes poked in it all work. A clear container like a glass jar or Cambro tub lets you monitor activity without opening it.

What a Poolish Does to Your Bread

Before getting into timing and readiness signs, it helps to understand why you’re bothering. A poolish improves bread in three specific ways.

Flavor. The 12-16 hour fermentation produces organic acids, esters, and alcohols that a 2-hour bulk fermentation simply cannot generate. The result is a sweet, nutty complexity — not sour like sourdough, but noticeably richer than straight-dough bread. The flavor difference is obvious in a side-by-side comparison.

Crumb structure. Poolish-based doughs produce a more open, irregular crumb with larger, unevenly distributed holes. The extended fermentation weakens the gluten network slightly (through protease activity over time), making it more extensible. Gas cells expand more freely during oven spring, creating the airy interior that defines great baguettes and rustic breads.

Keeping quality. Bread made with a poolish stays fresh 4-5 days compared to 2-3 days for straight-dough bread. The organic acids produced during the pre-ferment lower the dough’s pH slightly, which inhibits mold and slows staling.

Where and When to Ferment

Set the poolish in a spot that stays between 68-72 degrees F for the next 12-16 hours. Standard room temperature in most homes works. Warmer rooms speed fermentation; cooler rooms slow it.

The typical schedule: mix the poolish at 8-10 PM the night before you want to bake. By 8-10 AM the next morning, it’s ready.

If your kitchen is cold (below 65 degrees F): The poolish will take longer — up to 18-20 hours. You can compensate by adding slightly more yeast (up to 0.2% of flour), but it’s usually easier to just start it earlier.

If your kitchen is warm (above 75 degrees F): The poolish may be ready in 8-10 hours. Start it later in the evening, or check it earlier in the morning.

How to Tell When a Poolish Is Ready

Hamelman describes the readiness sign precisely: the surface will be domed and just beginning to recede at the center. This is the moment of maximum flavor and leavening power.

JayArr Bread

Poolish Timeline: Mix to Ready

12-16 hours at 68-72 F

0 hrs

Mix

Equal parts flour and water plus 0.1% yeast. Stir 30 seconds. Cover loosely.

1-4 hrs

Quiet

Not much visible. Small bubbles forming at edges. Yeast is multiplying.

4-8 hrs

Active

Surface becomes bubbly. Volume increases. Smells yeasty and slightly sweet.

8-12 hrs

Rising

Very bubbly throughout. Volume roughly doubled. Surface doming upward.

12-16 hrs

Ready

Dome just beginning to recede at center. Lacy, weblike surface. Sweet, nutty aroma. USE NOW.

16+ hrs

Over

Dome collapsed. Surface flat or concave. Alcoholic smell. Discard and remix.

Here’s the progression in more detail:

Hours 1-4: Not much visible. Some small bubbles forming at the edges.

Hours 4-8: Surface becomes bubbly. Volume starts increasing. Smells yeasty and slightly sweet.

Hours 8-12: Very bubbly throughout. Volume has roughly doubled. Surface begins to dome upward as gas production is vigorous.

Hours 12-16 (the window): Surface is domed and just starting to show a slight depression in the center. The top has a weblike, lacy appearance of interconnected bubbles. Aroma is sweet, nutty, and pleasantly yeasty. This is the target. Use it now.

Hours 16+ (over-fermented): The dome has fully collapsed. Surface is flat or concave. Liquid may have separated on top. Smell shifts from sweet to sharply alcoholic or vinegary. The poolish has exhausted its food supply and begun producing off-flavors.

What to Do If You Miss the Window

Life happens. If your poolish has gone past peak — surface collapsed, smell turned sharp — you have options.

Slightly past peak (dome just fully receded, within an hour or two): Still usable. The bread will be slightly more acidic with a less open crumb, but it will be good. Proceed with your recipe.

Well past peak (flat, alcoholic smell, 4+ hours over): The poolish has over-fermented. The resulting bread will taste flat and sour, and the pre-ferment won’t contribute much lift. It’s better to discard and start fresh. A new poolish takes 30 seconds to mix.

Need to delay on purpose? If you mix a poolish and realize you can’t bake the next day, refrigerate it. A poolish can hold in the refrigerator for up to 24 hours. The cold slows fermentation nearly to a stop. Pull it out 1-2 hours before you need it so it comes back toward room temperature and the yeast reactivates.

Poolish vs. Other Pre-Ferments

Poolish is one of several commercial-yeast pre-ferments, and each has a different character. Here’s how it compares to biga and pate fermentee at a glance.

JayArr Bread

Poolish vs. Other Pre-Ferments

Where poolish fits among commercial-yeast pre-ferments

Feature	Poolish	Biga	Pate Fermentee
Hydration	100%	60%	~65%
Contains salt	No	No	Yes (~2%)
Consistency	Liquid, bubbly	Stiff, dough-like	Standard dough
Ferment temp	68-72 F	60-65 F	65-70 F
Ferment time	12-16 hrs	12-16 hrs	12-16 hrs
Flavor	Sweet, nutty	Wheaty, firm	Complex, slightly sour
Crumb effect	Open, irregular	Tight, wheaty	Complex, even
Fridge life	24 hrs	24 hrs	2-3 days
Typical PFF	30-50%	20-30%	15-25%

Source: Hamelman (Bread, 3rd Ed.), Forkish (FWSY), and Reinhart (BBA). All three pre-ferments are commercial-yeast only — distinct from wild-yeast levain.

For a deeper comparison — including liquid and stiff sourdough levains — see the full pre-ferments guide.

Three Recipes Using Poolish

1. Poolish Baguettes (Hamelman’s Method)

This is the classic application. Hamelman’s poolish baguette uses 50% pre-fermented flour (PFF), meaning half the total flour goes into the poolish the night before.

Poolish (night before):

500g bread flour
500g water (68-70 degrees F)
0.5g instant yeast

Final dough (next morning):

All of the poolish
500g bread flour
20g salt (2% of total flour)
3g instant yeast
150-180g water (adjust for 68% total hydration)

Method: Combine poolish with final flour and most of the water. Autolyse 20 minutes. Add salt and yeast, mix to moderate gluten development. Bulk ferment 1.5-2 hours with one fold. Divide, pre-shape, rest 20 minutes, final shape into baguettes. Proof 45-75 minutes. Score with a curved lame at 30 degrees — 5-7 overlapping cuts. Bake at 460 degrees F with steam for 22-26 minutes.

The poolish produces an open, irregular crumb with thin, crisp crust and a sweet, complex flavor that straight-dough baguettes cannot match. For complete baguette shaping and baking technique, see our baguette guide.

2. Poolish Pizza Dough

Poolish works beautifully for pizza — the overnight fermentation develops flavor that a same-day dough can’t achieve, and the open crumb structure creates the charred, puffy cornicione (rim) of a great Neapolitan-style pie.

Poolish (night before):

250g bread flour or “00” flour
250g water (68-70 degrees F)
0.25g instant yeast

Final dough (next morning):

All of the poolish
250g bread flour or “00” flour
10g salt
2g instant yeast
25-50g water (adjust by feel)
10g olive oil (optional)

Method: Combine poolish with final flour and water. Rest 15 minutes. Add salt, yeast, and oil. Mix until smooth and slightly tacky. Bulk ferment 2 hours with two folds. Divide into 250-280g balls. Ball tightly on an unfloured surface. Proof 2-4 hours at room temp (or refrigerate overnight for next-day use). Stretch by hand and bake on a preheated steel or stone at the highest temperature your oven reaches — 500-550 degrees F for a home oven.

3. Poolish Sandwich Bread

A poolish elevates even a basic sandwich loaf. The pre-ferment adds keeping quality — poolish breads stay fresh 4-5 days compared to 2-3 for straight-dough versions — along with a more complex, slightly nutty flavor.

Poolish (night before):

200g bread flour
200g water (68-70 degrees F)
0.2g instant yeast

Final dough (next morning):

All of the poolish
300g bread flour
10g salt
4g instant yeast
30g sugar
30g butter (softened)
50-80g milk or water

Method: Combine poolish with final flour, milk/water, and sugar. Mix briefly, rest 15 minutes. Add salt, yeast, and softened butter. Mix on medium speed until dough passes the windowpane test — smooth, elastic, pulls away from bowl sides. Bulk ferment 1-1.5 hours. Shape into a tight log, place seam-down in a greased 9x5 loaf pan. Proof until dough crests 1 inch above the pan rim. Bake at 375 degrees F for 30-35 minutes until deep golden and internal temp reaches 190 degrees F.

Why Poolish Is the Best Starting Pre-Ferment

For bakers who haven’t worked with pre-ferments before, poolish is the ideal entry point for three reasons.

It’s forgiving. The 12-16 hour readiness window is wide compared to the precision required for sourdough levains. You have hours of usable time, not minutes.

It requires no special culture. Unlike sourdough, which takes days or weeks to establish, a poolish uses commercial yeast you already have. Mix it tonight, use it tomorrow.

The improvement is dramatic. The flavor difference between bread made with a poolish and the same bread made as a straight dough is immediately obvious. The crumb is more open and irregular, the flavor is sweeter and more complex, and the bread stays fresh longer. Once you taste the difference, you’ll find it hard to go back to mixing everything in one shot.

Frequently Asked Questions

What's the difference between a poolish and a sourdough starter?: A poolish uses commercial yeast and ferments for 12-16 hours before being used entirely in one bake. A sourdough starter is an ongoing culture of wild yeast and lactic acid bacteria that you maintain indefinitely through regular feedings. Poolish produces a milder, sweeter flavor — nutty and complex without the tangy sourness that sourdough cultures generate. A poolish is also dead-simple to time: mix it the night before, use it the next morning. Sourdough starters require learning to read the culture's activity level, and the timing window varies with temperature, feeding ratio, and flour type.
Can I make a poolish with whole wheat flour instead of bread flour?: Yes, and it produces a nuttier, earthier flavor. Whole wheat flour ferments slightly faster than white flour because the bran contains more available sugars and minerals, so your poolish may be ready in 10-14 hours instead of 12-16. You may also notice a thinner, more batter-like consistency because whole wheat absorbs water differently — the bran soaks up moisture over time. One approach: use a 50/50 blend of whole wheat and bread flour in the poolish for some whole-grain flavor without the faster fermentation timing.
How much poolish should I use as a percentage of total flour?: Forkish recommends 30-50% of the total flour in the recipe, and Hamelman's poolish baguette uses 50% pre-fermented flour. Within that range, more poolish means more flavor complexity and a more open crumb, but also faster final fermentation (since a larger portion of the dough is already fermented). At 30% PFF, you get a noticeable improvement over straight dough with a generous final fermentation window. At 50% PFF, the flavor impact is more pronounced but you need to watch the final dough more carefully — it will be ready to shape and proof sooner.
My poolish smells like alcohol — is it still good?: A mild alcohol smell is normal and expected — yeast produces ethanol as a byproduct of fermentation, and some of it accumulates in the poolish. The ethanol evaporates during baking and does not affect the final bread flavor. However, a strong, sharp alcohol or nail-polish-remover smell means the poolish is significantly over-fermented. At that point, the yeast has exhausted most of the available sugars and the flavor contribution will be diminished. If the dome has fully collapsed and the smell is aggressively alcoholic, it's better to start a fresh one — it only takes 30 seconds to mix.
Can I use active dry yeast instead of instant yeast for a poolish?: Yes. Dissolve the active dry yeast in the water before adding flour — active dry yeast needs to hydrate in liquid before it begins working, unlike instant yeast which can be mixed directly into flour. Use about 25% more active dry yeast than the instant yeast amount in the formula, since active dry yeast has a lower percentage of viable cells. So if the recipe calls for 0.25g instant yeast, use about 0.3g active dry yeast dissolved in the water first.
Do I need a kitchen scale to make a poolish?: Strongly yes. At the quantities involved — 0.25g of yeast is about 1/16 teaspoon — volume measurements aren't reliable. A basic digital scale that reads to 0.1g is inexpensive and transforms accuracy. If you only have a scale that reads to 1g, pre-mix a larger batch of yeast (say, 10g yeast + 90g flour) and use 2.5g of that blend as your 0.25g yeast equivalent. For more on the equipment that makes bread baking accurate, see our [bread baking equipment guide](/blog/bread-baking-equipment-guide/).
Can I double or scale a poolish recipe?: Yes. A poolish scales linearly — keep the flour:water ratio at 1:1 and the yeast at 0.1% of flour weight, and the timing stays about the same. A 500g poolish ferments in roughly the same 12-16 hours as a 100g poolish because the yeast-to-flour ratio is what controls the fermentation rate, not the absolute quantity. Larger batches may take 30-60 minutes longer simply because the center of the mass is slightly insulated from ambient temperature swings.