Sourdough Liquid Yeast

This form of Grumbieresatz (potato yeast) was normally prepared two days before baking. A new batch was started every week with residue from the last. In place of residue to activate it, I suggest active dry yeast. The starter can be kept dormant in the refrigerator for as long as ten to twelve days, but to keep it active it is best to store it in a warm place.