<human>: How can I make a sourdough starter?
<bot>: To make a sourdough starter, you will need to mix equal parts of water and all-purpose flour. Stir the mixture until it forms a dough. Allow the dough to ferment at room temperature for 12-24 hours, stirring it every few hours. Once the starter has risen and doubled in size, you can use it as a base for your sourdough breads.