Basic Sourdough Starter (With Potato)

Dissolve yeast in warm water in 3-qt glass bowl. Stir in milk. Stir in flour gradually. Beat until smooht. Cover with towel; let stand in warm, draft-free place until starter begins to ferment, about 24 hrs. (bubbles will appear on surface of starter) If starter has not begun fermentation after 24 hr, discard and begin again. If fermentation has begun, stir well; cover tightly with plastic wrap and return to warm, draft-free place. Let stand until foamy, 2-3 days. When starter has become foamy, stir well; pour into 1-qt crock or glass jar with tighlty fitting cover. Store in frig. Starter is ready to use when a clear liquid has risen to top. Stir before using. Use 1 c starter in recipe; reserve remaining starter. Add 3/4 c milk and 3/4 c flour to reserved starter. Store covered at room temp until bubbles appear, about 12 hrs, refrigerate. Use starter regularly, every week to 10 days. If the volume of the breads you bake begins to decrease, dissolve 1 t yeast in 1/4 c warm water. Stir in 1/2 c milk, 3/4 c flour and the remaining starter. *DO NOT USE SELF RISING FLOUR* NOTE: Start bread at night to bake in the morning -
or vice versa. Before adding the milk and flour to remaining starter, bake your bread and judge the volume