The Sourdough Framework is a free, open-source book on the science and craft of baking sourdough bread at home, by Hendrik Kleinwächter, the software engineer behind the YouTube channel The Bread Code. First published in 2022 under a CC BY-SA 4.0 license, it is available in nine languages as HTML, PDF and EPUB at the-sourdough-framework.com, and as a 250-page hardcover (ISBN 978-3-00-077702-8, The Bread Code, 2023) funded by more than 1,100 Kickstarter backers.

Unlike a recipe collection, the book explains the variables behind every recipe: flour, hydration, temperature, starter activity, fermentation and dough strength, and how to read your dough at each stage. Chapters cover the history of sourdough, how fermentation works, making and maintaining a starter, starter types, flour types, wheat and non-wheat sourdough, baking, mix-ins, bread types, storing bread, and a troubleshooting guide that diagnoses common problems from the crumb. Flowcharts and tables throughout.

The source is maintained on GitHub (hendricius/the-sourdough-framework), and the book was covered by Ars Technica in November 2024 ("Flour, water, salt, GitHub").