1 pkg. active dry yeast
2 c. lukewarm water
2 c. flour
1/2 c. sugar
1 c. water
1 c. milk

In a large glass jar, dissolve yeast in warm water. Add flour; beat until smooth. Let stand overnight at room temperature. Cover loosely and refrigerate for 5 days, stirring each day. On fifth day, add the sugar, water, and milk. Refrigerate, stirring daily for another 5 days before using. Starter may be kept in refrigerator indefinitely. Always replace used portion with equal amounts of flour and water.