Remove the starter from the refrigerator and allow it to come to room
          temperature. Measure out 1 l/2 cups of starter and put it into a 2quart
          mixing bowl. Add 1/2 CUpS flour and 1 cup tepid water (85°). Mix this
          well, cover, and allow to sit overnight, unrefrigerated. This is called
          "proofing," and when the batter is ready, the natural yeast will have
          spread throughout the dough and it will be bubbly and offer a strong sourdough
          odor.

          When ready to bake, measure out the amount of batter called for in the
          recipe and return the remaining batter to your starter bowl in the
          refrigerator. Remember that you must replenish your starter by adding back
          what you take out. Return the same amount of water and flour that you have
          removed. Just whip it up and stir it into the starter bowl.