1 cup milk, leave at room temperature until it sours and clabbers (goes thick). It should be covered with cheese cloth or net. This will take 5 to 7 days.

Add 1 cup flour to clabber, stir well. Cover with net and let stand at room temperature for 24 hours until very bubbly. It's now ready to use in recipes. To replenish, add equal amounts of milk and flour and stir well. Let stand (net covered) at room temperature for 24 hours and then store in refrigerator.

I use a 3 pound peanut butter bottle to keep my sourdough starter in. The amount of starter that clings to the sides is enough to make the new milk and flour replenish. I use 3 cups water and 1/2 cup powdered milk and 3 cups flour.