Expanding the Starter

A day before baking, when you anticipate making sourdough bread, begin by building the natural starter into a finished sourdough starter by adding flour and water. If your starter isn’t as vigorous as you’d like—it takes longer than 8 hours to double in volume—consider adding a small amount of yeast to hurry things along. This method of combining yeast with a natural starter is called the “mixed method.”

Day 7 or 24 hours before you’re ready to make bread: Combine 1 cup starter—don’t use it all, you want to maintain some for future projects—with 1 cup flour and 1 cup water and allow it to rise at cool room temperature for 24 hours. If you don’t have a cool place for the rising, let rise at room temperature for 4 hours and then transfer to the refrigerator for 20 more hours.