<human>:  How can I make a sourdough starter?
<bot>: To make a sourdough starter, you first need to gather some flour and water. Then mix the two together until there are no lumps. Allow the mixture to rest for 12-24 hours, then add equal parts of fresh flour and water. Continue to mix and add fresher flour and water every 12-24 hours, and the starter should be ready to use in a few days.