Mix the 1 cup warm water, 1-1/2 cups white flour and 1 tsp. each salt and sugar in a 2-cup measure. Add enough grated potato to make 2 cups. Place in a wide mouth glass jar or small mixing bowl (do not use metal or plastic) which will hold about 1 quart. Cover with a single thickness of cheesecloth to allow wild yeast from the air to settle into it for 24 hours. Stir well, cover tightly with a clinging transparent wrap which will cause the moisture to drip back and keep top of mixture from drying. Stir several times a day. In two or three days it will become foamy and very light. (The length of time depends on temperature. 80 ~85 is ideal. It can go a little below 80 without harm, only slowing the procedure a little, but if it goes much higher than 85 it will be spoiled.) Then stir well, pour into glass jar with screw-top lid and store in refrigerator at about 38 degrees. As soon as 1/2 inch of clear liquid has risen to the top it has ripened enough to start using. Do not be concerened if the mixture turns dark because of the raw potato during the fermentation period. It does not affect the bread made from it in any way and as soon as the starter is mature, it will become a snowy white. To renew starter: Add 1-1/2 cups white flour and 1-1/2 cups water each time it is used so that there are always 2 cups to bake with and 2 full cups to return to refrigerator. If for some reason it cannot be used regularly about twice a week, add 1 tsp. sugar and stirr well every three or four days. From: Breads and Coffee Cakes with Homemade Starters Shared By: Pat Stockett