Baking with Pre-ferments

May 12, 2020

What is a pre-ferment?

A pre-ferment is a piece of dough that has been made in advance of the bake and has been allowed to develop a culture of bacteria, typically over a period of 12 to 16 hours. This dough is then mixed in with the flour and other ingredients. Adding a pre-ferment lets you make lots of different types of delicious bread and provides lots of opportunities for experimentation.

Bread made with a pre-ferment is noticeably different to straight breads (aka those made without one). The inclusion of a pre-ferment has significant advantages, for example, these breads tend to last longer and taste better. They also use much less yeast (very useful if you can’t find any at the moment) and also tend to have thicker, chewier crusts.

There are three main types of pre-ferment: poolish, biga and Pâte Fermentée. Most recipes will use one of these, each being slightly different.

Poolish
As the name suggests, poolish has it origins in Poland but quickly became popular with French bakers when it was introduced in the 19th century. Poolish has a hydration of 100% (1 unit of water to each unit of flour) which means it is wet and sticky like batter. It is often used when making baguettes and has a wheaty, nutty taste.

Biga
With a hydration of around 50-60%, biga is much stiffer than poolish and looks a lot more like a piece of dough. Doughs made with biga tend to rise more than those made with poolish which expand sideways.

Pâte Fermentée
Literally ‘old bread’, pâte fermentée is an extra piece of dough that has been kept from a previous bake. Unfortunately, this dough doesn’t keep very well and will only last 48 hours in the open or a week in the freezer. It is perfectly fine to make this pre-ferment a day before the bake, much like biga or poolish.

For best results, pre-ferments should be used when they are at their ripest. Poolish will be covered in bubbles and small channels, biga and pâte fermentée should be domed slightly. A pre-ferment that has collapsed is over ripe and will make an inferior loaf.

There aren’t really any hard and fast rules for determining whether a pre-ferment is ripe and it mostly comes down to intuition and trial-and-error.