How to Make a Poolish Sponge

This makes enough for my baguette recipe, but of course it can be increased if need be for some other application. The amount of yeast employed in a poolish is tiny relative to the flour and water. So tiny, in fact, that for a poolish sponge this small, we’ll need to dissolve some instant yeast in water, then administer the solution in spoonfuls. Start by combining:

2 ounces water
1/8 teaspoon instant yeast

…in a small bowl.

Stir until the yeast is completely dissolved:

Fetch a slightly larger bowl, and put in it:

4 ounces all-purpose flour

plus

2 teaspoons of the yeast solution

Pour in:

4 ounces of water:

And stir with a fork until it’s all combined into a batter.

Cover with plastic wrap and leave it at room temperature for 12-16 hours until it looks about like so:

Nice and bubbly, yes? That’s what you want. And there you have it: one poolish. This will keep well in the fridge for two days.