BREAD TIP: Saving Yeast

With everyone baking during the COVID-19 shutdown, flour and yeast have become scarce, sometimes downright unavailable. Having taught thousands of students how to make bread, I share some of the responsibility for causing this shortage! I can't help you save flour, but you can grown your own yeast!

How is this possible? Well, yeast is a living thing, actually a single cell fungus. If you have just a little you can culture it into a whole bowl full!

Advanced yeast bakers use what's called a "pre-ferment" to improve the flavor, texture, and shelf life of bread. There are several types of pre-ferments. You could use any of these, but I'll focus on the "poolish" in this tip. It was originally developed by Polish bakers, and became fundamental to many artisan French breads. Here's how to do it:

1. Start with room temperature water that is free of chlorine. You could use spring or well water, but you can also boil tap water and let it sit overnight to cool while the chlorine dissipates into the air.

2. Choose a non-reactive container (avoid raw aluminum) that is 3 times the size of your poolish. For your first 1-cup learning batch, you need a 3-cup container. The poolish will double in size, and you should have extra room to stir and mix easily.

3. Mix in an equal amount of flour by weight. This translates to roughly 2 cups of flour to each cup of water.

4. For each cup of poolish, mix in ¼ to ½ teaspoon of yeast. For white flour, ¼ teaspoon is probably enough. For whole grain flours, ½ teaspoon might help raise the heavier dough.

5. Loosely cover allowing carbon dioxide gas to escape.

6. Allow to culture (grow) at room temperature until double in size. This will take several hours to overnight depending on how warm it is in your kitchen.

7. Once the poolish is very active (bubly), mix in salt. I recommend 1½ ~ 2 teaspoons of Diamond Crystal kosher salt (cut in half for non-iodized fine table salt).

8. Add the rest of the flour in your recipe to make a barely kneadable dough. Do not over-flour! You do not want a heavy, dense dough which will further slow the process down.

9. Set your dough to proof. Expect it to take much longer than if you had added the normal 2 teaspoons or more yeast. 2 ~ 3 hours is typical. Keep an eye on it! Do not over-rise, or it could implode in the oven during baking.

10. Bake your dough in a pre-heated oven at the time/temp specified in your recipe.

You can make a larger batch of poolish and use half for baking and feed the other half with equal amounts of water and flour to keep it going. This way you'll never run out of yeast! It's a little like sourdough starter, just not quite as acidic (sour). If it gets funky smelling, throw it out and start over.