How to Proof Yeast

You’ll need:

1 package (1/4 ounce) active dry yeast

1/2 cup water

1 teaspoon sugar

Step 1: Stir it Up

  • In a large bowl, give the yeast, water and sugar a little stir. The water should be warm enough—ideally between 105º and 115º—to really get the yeast going.
  • You may notice that some recipes don’t call for sugar in the proofing process, but adding a small amount at this stage provides the yeast with the energy it needs to create carbon dioxide (all those gassy bubbles that give bread its lift). And don’t worry—a teaspoon of sugar won’t impact the overall taste of the bread.
  • Test Kitchen tip: Feel free to substitute a bit of honey or agave syrup for the sugar—even a tablespoon of flour will do. These ingredients all serve as food for the yeast.

Step 2: Wait it Out

  • Be patient, and let the mixture stand for 5-10 minutes (this was always my big mistake—not letting it sit). This allows the yeast enough time to gobble up all that sugar and produce plenty of carbon dioxide. Once it’s nice and bubbly, it’s ready to be incorporated into your mixture.
  • If you notice that the yeast hasn’t bubbled much after 10 minutes, the yeast might be old. You can still use old yeast in a recipe, but it will take longer to rise. In general, though, be mindful of expiration dates, and be sure to store yeast in a cool, dry place—even in the fridge or freezer.