Yeast is a tiny plant-like microorganism, like algae, that can be found in soil, plants, and even in the air. It’s sometimes called the oldest plant cultivated by man, but it’s most commonly known for its role in making bread.
Yeast gives off the gas that makes bread rise. It does this by feeding on sugars in the flour and releasing carbon dioxide. The gas fills the dough with balloon-like bubbles, which produces an airy loaf.
If you run out of yeast or if you have an allergy, a yeast substitute may be a great alternative.
Common Yeast Substitutes
Baking soda and lemon. Combine equal parts lemon juice and baking soda to add up to the amount of yeast called for in the recipe. But don’t wait for the dough to rise; put it in the oven right away.
Milk and vinegar. If you’re worried that lemon juice might be too overpowering, you can use a combination of milk and vinegar instead. Mix milk and vinegar in a 1:1 ratio, and then combine that mixture in equal parts with baking soda to add up to the amount of yeast you need. You can also use buttermilk with baking soda. These ingredients also cut down on the rising time for the dough.
Double-acting baking powder. Baking powder is a complete leavening agent. Baking soda needs an acid component in order to release the gas for the dough to rise. Baking powder is made with baking soda and a dry acid, usually cream of tartar. You can substitute this ingredient in an equal ratio to the amount of yeast in the recipe.
Quick bread. If you’re comfortable with some changes to the final result of your baking, you might make a quick bread recipe. Quick bread is a kind that doesn’t need yeast to rise and can be an excellent solution when you're trying to avoid yeast.
Sourdough starter. Sourdough starter has naturally occurring yeast. It's made from water and flour and is used to make sourdough bread. Fermentation by a sourdough starter works in the same way as instant yeast does. It forms bubbles of carbon dioxide in the dough to make it rise. Some sourdough starters can be maintained for years, constantly fermenting to give a strong flavor and soft, chewy texture.
Make Your Own Sourdough Starter
You will need:
- 4 1/2 cups whole-wheat flour
- 5 cups all-purpose flour, plus extra for maintaining starter
- Water (room temperature)
1. Combine whole-wheat flour and all-purpose flour in a large container. In a separate bowl, mix 1 cup flour mixture and 2/3 cup water at a time until no dry flour remains. Cover with plastic wrap and let sit at room temperature until bubbly and fragrant, usually 48 to 72 hours. This is your starter. Make sure you don’t throw away the left over flour mixture!
2. Transfer 1/4 cup of your starter to a clean bowl or jar. Stir in 1/2 cup of the flour mixture and 1/4 cup water until no dry flour remains. Cover with plastic wrap and let your starter sit at room temperature for another 24 hours.
3. Repeat step 2 every 24 hours until your starter doubles in size, 8 to 12 hours after being fed. This process can continue for 10 to 14 days. At this point, your starter is mature and ready to be baked with or stored for future use.
- If baking, use your starter within 1 hour after it starts to deflate after reaching its peak size during the 8- to 12-hour window.
- If storing, transfer 1/4 cup of the starter to a clean bowl. Stir in another 1/2 cup of all-purpose flour and 1/4 cup water until no dry flour remains. Then, transfer your starter to a clean bowl and cover it loosely. Let it sit at room temperature for 5 hours before putting it in the fridge. If you’re not baking with your starter regularly, you'll want to repeat this "feeding" process weekly.
- When removing your starter from storage, you'll want to feed it once more before you bake with it. After letting it sit for 5 hours, transfer the amount of starter called for in your recipe to a second bowl. Cover and refrigerate for at least 12 hours or up to 18 hours. The remaining starter should be refrigerated and maintained as directed.