Crumble or sprinkle the yeast over the water in the measure, whisk in the sugar, and let rise for several minutes until it begins to foam. Whisk it again, then scrape into a 2 quart glass or plastic container. Whisk in the cup of flour, then the water, to make a mixture the consistency of pancake batter. Set uncovered at room temperature for several hours, until it foams and produces bit heavy bubbles. Stir it up, and leave overnight. May be used in place of the Silverton starter in any of her recipes.
AHEAD OF TIME NOTE: If not to be used the next day, cover and refrigerate. The batter will gradually turn into a sourdough; feed it and treat it in the same way as the finished Silverton starter. From: Richard Taylor