Getting Started with Sourdough: How to Make a Starter From Scratch

10. The Importance of Water and Temperature

Your sourdough starter needs water and warmth to grow. Feed your starter with a balanced mixture of flour and water. It’s no big deal to use tap water in your starter and for feeding. Most tap water has a low enough mineral content to not interfere with the starter. However, you may want to check if your tap water contains chlorine, as chlorine can interfere with or kill your starter. If your water is chlorinated, simply leave a cup of water out on the counter. The chlorine will evaporate naturally. Use tap or lukewarm water in your starter, depending on room temperature. Balance a warm room with cool water, or a cool room with warm water. Leaving your starter in the sun, however, can result in internal temperatures over 100°F, which can kill your starter. Just be mindful of water and temperature in starter maintenance.