I peel two apples and cut them up, peels and all. Cover them with water in a jar for 4 or 5 days . Keep covered. Then strain the water, throw out the apple. Add enough flour to make a very wet batter. Let that sit for a couple days or until you can smell the sour. I add a cup to my bread recipe. Feed the starter with 1/4 cup flour and 1/4 cup water.