Sourdough Starter

1 package active dry yeast
2 1/2 cups warm water (110 degrees F)
2 cups all-purpose flour, unsifted
1 tablespoon granulated sugar

In a 6-cup glass or ceramic container soften yeast in 1/2 cup warm water. Stir in remaining 2 cups water, flour and sugar. Beat mixture until smooth. Cover loosely with cheesecloth, folded into several thicknesses and let stand at room temperature until bubbly. This may take 5 to 10 days, depending upon the temperature of the room