Seed Culture

(recipe, Peter Reinhart)


Seed culture is the first step in making sourdough bread.


  1. 1 cup (4¼ ounces) dark rye or coarse whole rye (pumpernickel-grind) flour
  2. 3 cups (13½ ounces) unbleached high-gluten or bread flour
  3. 2¼ cups (18 ounces) water, at room temperature


  1. Day 1: Mix the rye flour and ¾ cup (6 ounces) water together in a bowl until they form a stiff ball of dough. Do not worry if the dough is very stiff, but be sure that all the flour is hydrated. Press this piece of dough into a 4-cup measuring beaker and place a piece of tape on the beaker to mark the top of the dough. Cover the beaker with plastic wrap and leave it at room temperature for 24 hours.
  2. Day 2: The dough should not have risen much, if at all, during this time. In a mixing bowl, combine the sponge from Day 1 with 1 cup (4½ ounces) unbleached flour and ½ cup (4 ounces) water, mixing with your hand or a spoon until all the ingredients are evenly distributed. The dough will be somewhat softer and wetter than before. Return this to the beaker, press it down, and replace the old tape with a new piece of tape to mark the spot. Cover with plastic wrap and ferment for 24 hours at room temperature. Do not be put off by the strong, unpleasant aroma of the dough; this will eventually brighten.
  3. Day 3: Check to see if there has been a rise in the dough. There will probably be some fermentation but not a lot, perhaps a 50-percent rise. Regardless, discard half of the starter (or give it to a friend to cultivate) and mix the remaining half with 1 cup (4½ ounces) unbleached flour and ½ cup (4 ounces) water, just like on Day 2. It will be a little wetter. Again, return it to the beaker. It should press down to the same height as on Day 2. Re-tape the beaker to mark the top of the dough, cover, and ferment for 24 hours.
  4. Day 4: The sponge should have at least doubled in size; more is even better. If it is still sluggish and hasn't doubled in size, allow it to sit out for another 12 to 24 hours. Otherwise, repeat as on Day 3, discarding half of the starter and mixing the remaining half with 1 cup (4½ ounces) unbleached flour and ½ cup (4 ounces) water, returning it all to the beaker as before. Cover and ferment until it at least doubles in size; this may take 4 to 24 hours. It is OK if it triples in size, but because it is now fairly soft and spongelike, it will not be able to sustain that large of a rise without falling. If it falls easily when you tap the beaker, that is the sign that your seed culture is ready to be turned into a barm, or mother starter.


Read more about making homemade bread in Melissa Lion's essay, "The sourdough apprentice."