Poolish vs Biga: Which Preferment Should You Use for Pizza Dough?

Poolish and biga are the same idea executed at two different hydrations, and almost everything people argue about downstream comes from that one number. A poolish is 100 percent hydration, equal weights of flour and water, and it pours. A biga is 45 to 50 percent hydration, and it is a stiff, shaggy lump you have to break apart with your hands. Both give a portion of your flour a long head start before the main mix, and both are free. Which one you want depends on whether you are after a soft, extensible dough or a strong, chewy one.

What is a preferment, and why bother with one?

A preferment is a portion of the recipe's flour and water, plus a very small amount of yeast, mixed the night before and left to ferment on its own. The next day it goes into the final dough as an ingredient. That is the whole concept.

The reason it works is that fermentation does two separate jobs and a fast dough only gets one of them. The obvious job is gas: yeast produces carbon dioxide and the dough rises. The less obvious job is chemistry: enzymes already present in the flour break long starch chains into simpler sugars, bacteria produce organic acids, and the whole mixture develops aroma compounds that simply do not exist in a dough mixed two hours before dinner. A preferment buys 12 to 18 hours of that chemistry on part of your flour without committing the whole batch to a long schedule.

There is a structural payoff too. The acidity a preferment develops conditions the gluten, making the final dough more extensible, which is the property that lets you stretch a base thin without it snapping back or tearing. That is why doughs built on a preferment usually feel easier to open, and why the guidance in the stretching guide is easier to follow with one.

A plain definition sentence before the arithmetic, because everything below depends on it: in baker's percentage, every ingredient is expressed as a percentage of the total flour weight, and flour is always 100 percent. The baker's percentage guide covers the mechanics and the percentage chart lists the standard ranges.

What exactly separates poolish from biga?

Hydration, and then five consequences of it.

Speed. Water mobilises enzymes. A 100 percent hydration poolish ferments noticeably faster than a 50 percent biga at the same temperature with the same yeast, so a poolish is typically ready in 12 to 16 hours where a biga wants 16 to 18.

Acid profile. Wet, oxygen-poor conditions favour lactic acid, which reads as mild, milky and sweet. Drier, more open conditions favour acetic acid, which reads sharper and more assertive. This is why a biga dough tastes more obviously fermented and a poolish dough tastes rounder.

Structure. A stiff biga develops gluten while it sits, because the strands are packed close enough to link. A slack poolish develops far less structure and instead breaks it down. So biga adds strength to the final dough and poolish adds extensibility.

Crumb. Poolish tends toward a softer, finer, more even crumb with a tender rim. Biga tends toward a drier, chewier crumb with larger irregular holes, which is the texture most people mean when they praise a Roman or contemporary Neapolitan rim.

Tolerance. A poolish has a fairly narrow peak and collapses into a slack, sour liquid if you leave it too long. A biga is slower and more forgiving at the edges, though it punishes you differently: an over fermented biga goes crumbly and cheesy-smelling and will never come together properly.

How do the two compare in a real 1,000 g dough?

Everything below is built on the same base recipe so the numbers can be checked against each other: four 250 g balls, so 1,000 g of total dough, at 65 percent hydration, 2.5 percent salt and 0.2 percent instant dry yeast. The total percentage is 167.7, so the flour is 1,000 divided by 1.677, which is 596.3 g. Water is 387.6 g, salt is 14.9 g and yeast is 1.2 g. Those four add back to 1,000 g, which is the check worth doing on any dough calculation you are handed.

The yeast column is 0.1 percent of the preferment flour, rounded to the nearest 0.1 g, which is why a 0.1 g resolution scale is the one tool this whole page depends on. Weighing 0.2 g of yeast by eye is not a thing anybody can do, and getting it wrong by a factor of three is the usual reason a poolish is already collapsed at breakfast.

How do you actually build the poolish version?

The night before, combine 178.9 g flour, 178.9 g water and 0.2 g instant dry yeast. Whisk it to a smooth batter, cover it, and leave it at room temperature for 12 to 16 hours. It will be domed, bubbled and smelling faintly of beer when it is ready.

The next day, add the remainder: 417.4 g flour, 208.7 g water, 14.9 g salt and 1.0 g instant dry yeast. Check the arithmetic yourself, because it should always close. Flour: 178.9 plus 417.4 is 596.3. Water: 178.9 plus 208.7 is 387.6. Yeast: 0.2 plus 1.0 is 1.2. Salt is untouched at 14.9. Total dough: 358.0 g of poolish plus 642.0 g of final mix is 1,000.0 g, which is four 250 g balls.

Two notes on that split. Salt never goes into a preferment, because salt slows fermentation and the preferment exists to ferment. And the yeast split is a choice rather than a law: many bakers put the entire yeast quantity into the poolish and add none at the final mix, in which case the total yeast drops and the bulk ferment lengthens. Either works, but do not do both by accident.

Mix the final dough, bulk ferment it until it is visibly livelier, then divide into four 250 g balls and rest them until they are relaxed and domed. A graduated straight-sided container turns "has it risen enough" from a guess into a reading, which is the single most useful piece of equipment in this whole process. The proof time calculator handles the timing, and the poolish and biga calculator will rerun all of the arithmetic above for any batch size and any preferment share.

How do you build the biga version instead?

The night before, combine 178.9 g flour, 89.5 g water and 0.2 g instant dry yeast. It will not come together into a smooth dough and it is not supposed to: rub the yeast and water through the flour until it is a rough, crumbly mass with no dry pockets, press it into the container and cover it. Leave it 16 to 18 hours, ideally somewhere a little cooler than you would put a poolish.

The next day, add 417.4 g flour, 298.1 g water, 14.9 g salt and 1.0 g instant dry yeast. The check again: flour 178.9 plus 417.4 is 596.3, water 89.5 plus 298.1 is 387.6, yeast 0.2 plus 1.0 is 1.2, salt 14.9. Preferment 268.6 g plus final mix 731.4 g is 1,000.0 g. Same dough, same hydration, different route.

The practical difference on the day is mixing. A poolish disappears into the final dough in seconds because it is a liquid. A biga has to be broken into small pieces and worked in, and it will fight you for the first few minutes. A bench scraper makes that far less unpleasant. If you are mixing by hand, dissolve the extra water and yeast first, then tear the biga in.

How long does each need, and how much does temperature move it?

Enormously, and this is the variable people ignore. Yeast activity roughly doubles for every 17F, about 9C, that dough temperature rises. That is a working approximation rather than a law, but it is close enough to plan with. A preferment that is perfect after 12 hours in a 70F kitchen will be collapsed and sour after 12 hours in an 80F one, and still sluggish after 12 hours in a 60F one.

So the times in the table assume roughly 65F to 70F. If your kitchen sits warmer, either shorten the schedule, cut the preferment yeast, or use cooler water. If it sits colder, do the reverse. A instant-read probe thermometer reads final dough temperature, which is the number that actually controls fermentation and the one almost nobody measures. The fermentation time by temperature chart maps the relationship out.

Judgement beats the clock in both cases. A ready poolish is domed or just starting to flatten, covered in bubbles of mixed size, and smells sweet and slightly winey. A poolish that has gone flat with a sharp, solvent smell is past its peak and will make a slack dough. A ready biga has roughly doubled, smells nutty and yeasty, and pulls apart to show a web of strands inside. A biga that smells sharply cheesy has gone too far.

Which should you use, poolish or biga?

Picking a side for each situation rather than hedging:

Neapolitan pizza in a 900F oven: use poolish. A 60 to 90 second bake needs a dough that inflates fast and a rim that stays tender, and extensibility is what lets you open a 250 g ball to 11 or 12 inches without fighting it. Pair it with 00 flour and follow the Neapolitan dough guide.

New York style in a 550F to 700F oven: use biga. A five to eight minute bake rewards strength and chew, and the drier preferment supplies both. It also suits the bread flour that a longer bake wants. The New York dough guide has the full formula.

You want the biggest, most open rim: use biga at 50 percent of the flour. That is the contemporary Neapolitan and Roman approach, and the table above gives you the numbers: 298.2 g flour, 149.1 g water and 0.2 g yeast in the preferment. Expect a stiffer dough, a longer mix and a more assertive flavour.

This is your first preferment: use poolish at 30 percent. It is easier to mix, easier to read because a liquid shows its state visually, and easier to fold into a final dough. Biga is not harder to make, it is just harder to judge the first time.

Your schedule is unpredictable: use biga, and keep it cool. Its slower, drier fermentation gives a wider usable window than a poolish, which peaks and then falls away fairly quickly. If your evenings vary by two hours, that tolerance is worth more than any flavour difference.

You already cold ferment and are happy with the result: use neither, yet. A 24 to 72 hour cold ferment already delivers much of what a preferment gives, and stacking both without dropping the yeast is how people end up with over proofed, blistered, unusable balls. Read the cold fermentation guide first, then add a preferment as a second step with the total yeast reduced.

What actually goes wrong with each one?

The two failure modes are opposite and both are timing problems dressed up as recipe problems.

An over fermented poolish looks flat and thin, smells sharply of acetone or nail varnish, and produces a final dough that is slack, sticky and tears when you stretch it. The cause is almost always too much yeast for the room temperature, not too many hours. Cut the preferment yeast to 0.1 g and the same schedule usually works.

An over fermented biga goes crumbly, dries at the edges and smells cheesy or ammoniac. It will never disperse properly into the final dough and you will find dense grey lumps in the finished crust. Keep it covered, keep it cooler than the poolish, and press it down into the container so less surface is exposed to air.

Under fermentation is easier to spot and easier to fix: the preferment barely moves, the final dough is tight and springy and snaps back when you open it, and the crust bakes pale with a tight crumb. Give it more time, or move it somewhere warmer, and check the water temperature you started with. Store the finished balls in straight-sided proofing boxes or a graduated proofing container so that whichever problem you have, you can see it happening rather than discovering it at the peel.