1 pkg. active dry yeast
1 1/2 c. warm water
1 1/2 c. all-purpose flour
1 tbsp. sugar

Dissolve yeast in water. Add flour and sugar. Cover and set aside at room temperature overnight.

Refrigerate until ready to use, at least 3 days before using. Stir once a day. When some starter is used, replace with 1/2 cup flour, 1 teaspoon sugar, 1/2 cup warm water for each cup of starter used.