
Sourdough Starter Recipe: How to Make One from Scratch (Day-by-Day Guide)
Jump to Section A sourdough starter is a live, fermented mixture of flour and water containing wild yeast and lactic acid bacteria (LAB) that naturally exist in flour, the air, and on your hands. When fed regularly, these microorganisms multiply and



![[Image: Thermometer inside a refrigerator showing temperature reading (35–40°F range)]](https://sourdougharchive.com/wp-content/uploads/2026/03/Thermometer-inside-a-refrigerator-showing-temperature-reading-35–40°F-range-300x167.jpg)
![[Image: Simple chart showing fermentation speed at 68°F, 75°F, and 80°F—visual representation showing bulk fermentation and final proofing durations side by side at each temperature]](https://sourdougharchive.com/wp-content/uploads/2026/03/Simple-chart-showing-fermentation-speed-at-68°F-75°F-and-80°visual-representation-showing-bulk-fermentation-and-final-proofing-durations-side-by-side-at-each-temperature-300x164.jpg)


