After choosing one of the above recipes, create the leaven by discarding 75 percent of the starter then adding 100 grams of flour and 100 grams of water to remaining 25 percent of the starter. Allow this to sit at room temperature for 12 hours. At the end of the 12 hours, your leaven is ready to go. Just be sure not to add all of the leaven to the final dough recipe; ins