Sourdough Discard: Not all sourdough discard is created equal. Discard that has been sitting in the fridge for a month will be more sour than discard sitting for a day or two. Using older discard can alter or deepen the sourdough flavor. If you don't want much sourdough flavor and are making this recipe to use up discard, use a "newer" or less-sour discard. If you want to taste the sourdough flavor, choose a discard that has been in your refrigerator for awhile.