Calculator
Poolish and biga calculator
Split a dough into a preferment and a final mix. A poolish here starts at equal flour and water. A biga starts at this site’s stiffer share. King Arthur’s published formulas stay in their own tables, because their yeast is not all in the preferment.
Quick answer. On 1000 g of flour, this site’s poolish starting point is 30% of the flour at 100% water: 300 g flour and 300 g water, plus all 2 g of the formula’s instant yeast. Salt stays in the final mix. Those shares are editable, and they are not the King Arthur formulas in the tables below.
Weights
Poolish: 30% of the flour at 100% water. Every gram of the formula’s instant yeast is in the preferment. Salt, oil, and sugar stay in the final mix.
| Ingredient | Weight |
|---|---|
| Flour | 300 g |
| Water | 300 g |
| Instant yeast | 2 g |
| Ingredient | Weight |
|---|---|
| Poolish | 602 g |
| Flour | 700 g |
| Water | 350 g |
| Salt | 20 g |
| Oil | 0 g |
| Sugar | 0 g |
| Instant yeast | 0 g |
Whole dough: 1,000 g flour, 650 g water, 65% water on the flour, 2 g instant yeast at 0.2%.
How the split is calculated
Flour in the preferment is total flour times the flour share. Water in the preferment is that flour times the preferment hydration. Instant yeast in the preferment is total flour times the yeast percent. The final mix gets the rest of the flour and the rest of the water, plus all of the salt, oil, and sugar, and no further yeast. If the preferment asks for more flour or water than the dough contains, the result stops instead of showing a negative weight.
That yeast rule is this site’s, shared with the pizza dough calculator. It is not how the two King Arthur formulas below are written. Their poolish and biga hold a little yeast, and the final dough holds the rest. The poolish and biga guide walks through a Roman example on the pizza preset. This page is the calculator.
What King Arthur says a poolish and a biga are
Their professional reference defines a poolish as equal weights of flour and water, a small amount of yeast, and no salt. The yeast is not one number: an 8-hour preferment needs more than a 14–16 hour preferment, and a 65°F room needs more than a 75°F room. A biga is an Italian preferment that can be stiff or as loose as 100% hydration. It is flour, water, and a little yeast, with no salt. The yeast can be as little as 0.1% of the biga flour. It ripens for at least several hours and for as much as 12–16 hours.
French bread with poolish
The professional formula prints 3.3 kg of flour and 3.3 kg of water in the poolish, which is 33% of the 10.0 kg total flour, at 100% hydration. Yeast in the poolish is 0.007 kg, and their table prints that as 0.2% of the poolish flour. The final dough then takes 0.103 kg of yeast. The poolish itself is left “until ripe,” with a note to adjust the yeast. Desired dough temperature is 75°F. Bulk fermentation is 2 hours with a fold after 1 hour. The final proof is about 1 hour. The oven is 460°F.
| Ingredient | Weight | Baker’s % |
|---|---|---|
| Flour | 10.0 kg | 100% |
| Water | 6.7 kg | 67% |
| Salt | 0.2 kg | 2% |
| Yeast | 0.11 kg | 1.1% |
| Total yield | 17.01 kg | 170.1% |
| Ingredient | Weight | Baker’s % |
|---|---|---|
| Flour | 3.3 kg | 100% |
| Water | 3.3 kg | 100% |
| Yeast | 0.007 kg | 0.2% |
| Total yield | 6.607 kg | 200.2% |
| Ingredient | Weight |
|---|---|
| Flour | 6.7 kg |
| Water | 3.4 kg |
| Salt | 0.2 kg |
| Yeast | 0.103 kg |
| Poolish | 6.607 kg |
| Total yield | 17.01 kg |
Ciabatta biga
The ciabatta formula says pre-fermented flour is 30%. The biga is 3 kg flour and 1.8 kg water, which is 60% hydration, and 0.003 kg yeast, 0.1% of the biga flour. It ripens about 16 hours at room temperature. The final dough holds 0.117 kg of yeast. Desired dough temperature is 75°F. Bulk fermentation is 2 hours with a fold after 1 hour. The dough is divided into 0.57 kg rectangles, proofed about 1 hour, and baked at 460°F for about 36 minutes at that weight.
This site’s biga button starts at 40% of the flour and 50% hydration. That is not the ciabatta pair of 30% and 60%. Put those numbers in the form if you want to scale the flour and water shares. The form will still put all of your yeast percent in the biga, which the ciabatta formula does not do.
| Ingredient | Weight | Baker’s % |
|---|---|---|
| Flour | 10 kg | 100% |
| Water | 7.6 kg | 76% |
| Salt | 0.2 kg | 2% |
| Yeast | 0.12 kg | 1.2% |
| Total yield | 17.92 kg | 179.2% |
| Ingredient | Weight | Baker’s % |
|---|---|---|
| Flour | 3 kg | 100% |
| Water | 1.8 kg | 60% |
| Yeast | 0.003 kg | 0.1% |
| Total yield | 4.803 kg | 160.1% |
| Ingredient | Weight |
|---|---|
| Flour | 7 kg |
| Water | 5.8 kg |
| Salt | 0.2 kg |
| Yeast | 0.117 kg |
| Biga | 4.803 kg |
| Total yield | 17.92 kg |
Questions
- Does this form use King Arthur’s yeast split?
- No. This calculator puts all of the formula’s commercial yeast in the preferment, which is how the pizza dough calculator on this site works. King Arthur’s French-bread poolish keeps most of the yeast for the final dough: 0.007 kg in the poolish and 0.103 kg in the final mix. That split is in the cited table, not in the form.
- What is a poolish?
- King Arthur’s professional reference defines a poolish as equal weights of flour and water, a small amount of yeast, and no salt. The form starts at 100% preferment hydration for that reason. The 30% of total flour is this site’s starting share, not a figure from that page.
- What is a biga?
- King Arthur describes a biga as an Italian preferment that can be stiff or as loose as 100% hydration, with no salt, and with yeast that can be as little as 0.1% of the biga flour. Their ciabatta formula puts 30% of the flour in a biga at 60% hydration and lets it ripen about 16 hours. This form’s biga starts at 40% of the flour and 50% hydration, and that pair is labeled as this site’s starting point.
- Where do salt, oil, and sugar go?
- In the final mix. The preferment on this form is flour, water, and the formula’s yeast. King Arthur’s poolish and biga notes also say those preferments are mixed without salt.
- What if the preferment wants more water than the dough?
- The result stops, with the same kind of message as the pizza calculator, instead of showing a negative weight to add. Lower the preferment flour, lower its hydration, or raise the dough’s water.
Last reviewed 1 November 2026.
Sources
The poolish definition, the biga range, and the two professional formulas are from King Arthur. The 30% poolish and the 40% / 50% biga are this site’s starting points. The form puts all of the formula yeast in the preferment; the cited formulas do not.