Sourdough Starter | Make a Natural Starter with Flour and Water

In a glass jar, use a fork to mix 50 g whole-wheat flour with 50 ml lukewarm water until it has the consistency of thick crepe batter. Do not seal the jar tightly; cover it with cheesecloth secured by a rubber band so the starter can get air. Mark the initial level of the mixture on the outside of the jar.

Starting on the second day, discard half of the mixture in the jar at the same time each day. Replace it with 50 g flour and 50 ml water, then stir. Discarding is essential: otherwise acid builds up and overwhelms the starter. Use whole-wheat flour for the first two days, then switch to bread flour.

Starting on the fifth day, check whether the starter doubles in volume within four to six hours after feeding; the tape mark will show you. Drop a spoonful of starter into a glass of water: if it floats, it is full of gas and ready to bake with; if it sinks, keep feeding it for a few more days. It should smell somewhere between yogurt and apple; a sharp acetone smell is a sign that it is hungry.