National Sourdough Bread Day

The earliest evidence comes from Egypt around 1500 BCE, where bakers figured out that a paste of flour and water, left out long enough, would begin to bubble on its own. The loaves they baked rose; the bread kept better; the flavor was tangier and more interesting. For the next 3,000 years, that was simply how bread was made.

Commercial yeast didn't exist until the 1860s. Industrial bread got faster and blander; sourdough got relegated to the niche. But it never fully disappeared. In 1849, a French-born baker named Isidore Boudin arrived in San Francisco during the Gold Rush and found local wild yeasts so flavorful that he built a business around them. The Boudin mother starter has been fed continuously since. It is older than the state of California.

Then came 2020. When the pandemic sent Americans home for weeks on end, millions of them decided this was the moment to finally make bread. Flour disappeared from grocery shelves nationwide. Instagram filled with proof shots. "Sourdough" became one of the most-searched terms on Google. Starters multiplied; some survive to this day, named and fed and passed between friends like heirlooms. That's the part of sourdough culture we're honoring today.

Four reasons your great-great-grandparents knew and we're just rediscovering:

A living colony of wild yeast and lactic acid bacteria, cultivated from nothing but flour and water. Once established, it can last generations. Here's the simplest path in.

Every baking culture has its own sourdough. Six worth tasting (or making) at least once.