To Make a Sourdough Leaven

Natural leavens take a few days to get going. They need to be kept in a warm room and out of draughts. If it is too cold, they will take very much longer to ripen, and then taste too sour. Luckily for us, they keep well in a refrigerator. If you want to start a leaven and use it once a week, you can pinch off a piece of dough weighing approximately 225 g/8