What Are Pre-Ferments and Why You Should Use Them

TLDR:
Preferments are partially fermented dough added to a final mix to boost flavor, texture, and performance in less time. Poolish is wet, biga is firm, and sourdough starter uses wild yeast, but all work by adding aged dough to fresh dough.

Using a preferment lets bakers achieve long fermentation flavor on a same day schedule.

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Twenty or thirty years ago, most home bakers had never heard the term preferment. Today, anyone making bread or pizza dough is curious about them. Poolish, biga, sponge, sourdough starter. What are they, and why do we use them?

The answer is simple. There is only one reason to use a preferment. It makes a better product.

A preferment is dough that has already fermented before it is added to the final mix. When you add it, you are essentially putting aged dough into fresh dough. This brings more flavor, better performance, and improved texture in less time.

Flavor normally develops through long fermentation. If maximum flavor takes eight to ten hours, adding twenty to thirty percent prefermented dough can cut that time in half. You can often reach the same flavor and structure in four to six hours. That is why bakeries working on same day production rely on preferments, while many home bakers use long cold fermentation instead.

The two most common yeasted preferments are poolish and biga.

Poolish

Poolish is a very wet preferment made with equal parts flour and water. This is known as one hundred percent hydration. It uses a tiny amount of yeast and ferments slowly at room temperature for twelve to twenty four hours. The result is a bubbly, spongy mixture that adds sweetness, aroma, and extensibility to dough.

Biga

Biga is a firmer preferment. Its hydration is usually similar to the final dough. For example, a baguette dough at sixty six percent hydration might use a biga at the same level. Like poolish, biga contains flour, water, and a small amount of yeast, usually without salt.

Salt is typically left out of preferments because it slows fermentation. Since the yeast quantity is already very small, bakers usually let fermentation proceed freely unless they are working in very warm conditions.

Sourdough Starter

Sourdough starter is another type of preferment. The principle is the same, but the leavening comes from wild yeast and bacteria rather than commercial yeast. Sourdough starters can be wet or firm, just like poolish and biga, and they add complexity along with natural leavening power.

When you add a preferment to your final dough, you are effectively aging the dough instantly. A freshly mixed dough can behave and taste like one that has already been fermenting for hours. This is why preferments remain one of the most powerful tools in baking.

Used thoughtfully, they allow bakers to balance time, flavor, and quality while keeping production practical.

May your crust be crisp and your bread always rise.