From Guest Chef Lucas Knapp
Mix thoroughly 1/2 C Flour and 1/2 C filtered Water. Cover with a cloth and leave in a warm place overnight. After 24 hours mix in 2 Tbs flour plus 2 Tbs filtered water every day. When starter is bubbly, it’s ready to use in baked goods. Refrigerate when not in use.
For advanced sourdough starter care (after the initial bacterial colonies are established – about a week), discard half (or use for baking) and replace with fresh water and flour to prevent the yeast from starving due to overpopulation.