How to feed sourdough starter

You’ve successfully made — or bought — a sourdough starter. Congratulations! Now you’ll need to regularly feed your starter to keep it alive and active for bread baking.

To feed sourdough starter, you simply discard some of the existing starter, then replace it with flour and water. Essentially, you’re giving the starter’s microorganisms food (in the form of flour) to keep them happy and healthy. Once fed, the starter will feast on the new food source, causing it to become active and bubbly, doubling in volume before it exhausts itself and begins to sink back down.

How to feed sourdough starter 

As outlined in our recipe for Feeding and Maintaining Sourdough Starter: Take 1/2 cup (113g) of the starter and place it in a medium-sized bowl. Discard the rest of the starter. (Or bake with it! See recipes to bake with discard starter here.)

Add 1/2 cup (113g) lukewarm water (tap water is fine) and a scant 1 cup (113g) unbleached all-purpose flour. Stir until everything is well combined, then return to its jar or crock. (Notice that you’re combining equal parts flour, water, and starter, by weight. That’s really the key, and that number can be flexible, as you see in our recipe for A Smaller Sourdough Starter; it’s essentially the same feeding method, but just 20g of starter, water, and flour!) 

Cover the container; it shouldn’t be completely airtight, but you also don’t want the starter drying out, so a kitchen towel isn’t suitable. The lid of a sourdough crock is designed perfectly for this; a loosely screwed on Mason jar lid is also suitable.

Your starter has now been fed! At this point, you can either leave your starter out at room temperature or place it in the fridge. Read below to determine the timeline that fits you.

How often to feed sourdough starter

Generally, there are two routines you may choose to regularly feed your sourdough starter. Depending on your choice, here's how often to feed sourdough starter: 

• Twice daily at room temperature: If you’re a regular sourdough baker, the best way to have ripe starter when you need it is to keep your starter on the counter at room temperature and feed it twice daily, about every 12 hours. 
• Once a week in the fridge: If you’re a more casual sourdough baker, it’s easiest to keep your starter in the fridge and feed it once a week. (We recommend leaving it on the counter for a few hours after feeding to start fermenting before returning it to the fridge.) Then, a day or two before you want to bake, give it a couple of feedings at room temperature before using it to bake.

Julia A. Reed

When is sourdough starter ready to bake? 

Sourdough bread recipes typically call for “ripe sourdough starter.” This refers to starter that has been fed and then doubled in volume and is showing signs of just beginning to deflate. The timing will be different depending on your sourdough starter and conditions, but generally, this occurs roughly eight hours after being fed. See more: Ripe sourdough starter: Here's what that means. 

Ready for more sourdough baking? Dive into our guide on How to Bake Sourdough, which includes technique videos, frequently asked questions, and expert advice.

All photography by Rick Holbrook; food styling by Kaitlin Wayne, unless otherwise noted.