Poolish (1:1 Flour to Water, 100% Hydration Preferment)

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Bread flour (or 00 flour) — Higher-protein flour better tolerates the long fermentation

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Water (room temperature) — Equal weight to flour; slightly cool water for longer ferments

0.1–0.5% of flour weight

Instant yeast — Less yeast = longer, cooler ferment = deeper flavor; 0.1% for overnight at 18°C

Whisk flour and water together until fully combined with no dry lumps. Stir in the yeast. Cover and ferment at 18–21°C for 12–16 hours (adjust yeast quantity inversely to time). The poolish is ready when it domes at the surface and just begins to recede at the center — this indicates peak fermentation activity. Incorporate into the final dough immediately, reducing final-dough water by the water already in the poolish.

• The poolish is over-fermented if the surface is heavily wrinkled and sunken — the gluten network has collapsed; reduce yeast or fermentation time next bake.
• Use water at 18–20°C for an overnight poolish; warmer water speeds fermentation unpredictably.
• When calculating final dough hydration, subtract the water already in the poolish from the total water called for.
• Poolish-based doughs are more extensible but can be slack — a gentle lamination fold in the early bulk works better than aggressive kneading.
• Bakers' percentages apply: if the poolish uses 200g flour in a 1000g total-flour recipe, that is a 20% preferment level.

• Short poolish

  0.5% yeast, 6–8 hours at room temperature; milder flavor, useful for same-day baking schedules

• Cold retard poolish

  0.1% yeast, 12 hours at room temp then refrigerated up to 48 hours; pronounced acidity and complexity

• Whole-wheat poolish

  Substitute 20% of flour with whole wheat; accelerates fermentation and adds earthy, nutty notes

• Rye poolish

  Small addition of dark rye (10%) intensifies enzymatic activity; watch carefully for over-fermentation

• Biga (60–65% Hydration Preferment)

  The stiff Italian counterpart; less water produces different organic acid balance and tighter crumb

• Preferment to Final Flour Ratio

  Governs how much of the total flour is pre-fermented in any poolish formula

• Desired Dough Temperature Formula (DDT)

  Water temperature for the poolish itself should be calculated to hit a target preferment temperature

1. 1.The Bread Baker's Apprentice — Peter Reinhart (Ten Speed Press, 2001)
2. 2.Advanced Bread and Pastry — Michel Suas (Cengage, 2009)
3. 3.Modernist Bread — Myhrvold & Migoya (The Cooking Lab, 2017)

Confidence: high