Yeasted preferment (Sponges)

Pâte fermentée means fermented dough (flour/water = 1.5/1) which is essentially "old dough" that is starting to ferments. It can be specially prepared a 12 to 24h before baking or it is a piece leftover dough from last time baking. The dough becomes slightly acidic due to the starting fermentation. This method is often used for French baguettes but it also advantageous when baking a rich dough with a lot of fat and sugar. Note: Once a Pâte fermentée had rested for an additional 10 hours of age, the French named it Levain de Chef.

In contrast to the "pâte fermentée",  polish contains much more water (flour/water = 1/1) and thus the dough is comparable to a wet sponge.

Biga is a preferment, which contains more flour than water (flour/water/ = 2/1) is very stiff. It needs to ferment in the fridge for at least 16 hours to develop some acidity and a complex, nutty flavor. The week acidity helps to improve the gluten network as well.

It is a good replacement for the sweet starter in recipes, which use a combination of starter and bakers yeast.