The Crumb Lab is an independent sourdough site made of three things: a free baking calculator, a recipe collection, and a library of in-depth guides on fermentation, hydration, shaping and scheduling. It exists to help home bakers understand why sourdough behaves the way it does, not just follow steps.
What You'll Find Here
The baking calculator lets you design flour blends, see hydration ratios, and build a baking schedule around your kitchen temperature and available time. The recipe collection covers breads, bagels, flatbreads, and ways to use discard. The blog goes deeper on topics like starter care, cold proofing, flour choice and troubleshooting.
Our Approach
Sourdough depends on your flour, your starter and your kitchen, so we favor frameworks over rigid recipes. Expect ranges, the reasoning behind them, and notes on what to adjust when your dough behaves differently. Treat timings and hydration as starting points and learn to read the dough.
How the Guides Are Made
The guides and recipes on The Crumb Lab are written with the help of AI and edited and published by the site owner. They are a synthesis of widely published baking technique and food-science knowledge, not a record of one person's personal bakes. We say so plainly because you should know what you're reading.
That means the articles do not describe personal anecdotes or first-hand test results, and you should treat timings, hydration and temperatures as starting points to adjust to your own flour and kitchen. The baking calculator is a working tool you can check against your own dough.
Accuracy and Corrections
Baking results vary, and we'd rather say so than overpromise. Where an article relies on research rather than baking technique, we try to keep claims modest and say when the evidence is mixed. Articles are dated, and we revise them when we find mistakes.
Nothing here is medical or nutrition advice. For dietary needs or health conditions, including diabetes and celiac disease, talk to a qualified professional.
If you spot an error, or a technique didn't work in your kitchen, please tell us on the contact page.
Privacy and Advertising
The calculator runs in your browser and stores its settings locally on your device. We don't ask you to sign up and we don't run a newsletter. Some pages may show ads served by Google AdSense, which can use cookies as described in our privacy policy.