Poolish: A Liquid Pre-Ferment for Airy Dough

Polish is a liquid pre-dough, simple to prepare and easy to understand: a thick batter made of equal amounts of flour and water, with a pinch of yeast, which turns into a sea of bubbles within hours. It is the basis for classic French baguettes and Italian pizza styles with a delicate and airy texture.

The basic relationships

• Hydration: 100% - the weight of water is equal to the weight of flour. The result is really liquid, like thick batter.
• Yeast: a tiny amount, around 0.1 to 0.2 percent of the weight of the flour. Less than it seems - and on purpose, to allow slow and long fermentation without early collapse.
• Fermentation time: 12 to 16 hours.
• Temperature: Normal room temperature, around 20 to 22°C. No need for a particularly cold place.

how to prepare

1. Mix flour, water and yeast in a bowl until a uniform and smooth mixture - with a spoon or a dough beater, without kneading.
2. Cover with plastic wrap or a lid. The high amount of water protects it from drying out better than Biga, but it's still worth covering.
3. Leave at room temperature for the duration of the fermentation, and don't mess with it in the meantime.

How do you catch him exactly at the peak?

Polish goes through stages that can be seen with the eye: first it is filled with small and uniform bubbles, then it swells and arches upwards, and finally - at the peak moment - craters and wrinkles begin to form in the center and it sinks slightly. This is exactly the moment to use it. If you wait too long, it becomes sour and sharp, and loses the delicacy for which you worked on it in the first place.

Unlike Biga, it's easy to miss the right moment with Polish-it moves quickly. Timing is the name of the game.

Mix in the final dough

Because it is liquid, polish mixes directly with the other liquids in the paste without having to crumble or cut it. And since the early fermentation has already created a significant part of the flavor and structure, the amount of commercial yeast in the main pulp is significantly reduced.

Common mistakes

• Add more yeast to speed it up. This is exactly what makes it too sour and brings the collapse closer.
• leave it warm. Polish is much more sensitive to temperature than biga and develops quickly accordingly.
• Plan it for a whole night in an Israeli summer. It is better to schedule the 12-16 hour window for the hours when you are actually at home.
• Measure yeast by eye. In such small amounts, the difference between 0.1% and 0.4% is the difference between a successful polish and a bad polish.