Some might believe you need a cherished heirloom starter passed down from your grandmother to make sourdough, but the truth is, all you need is flour, water, and a bit of patience. Crafting a sourdough starter, also known as a levain, at home is not only easy but also a fun and rewarding process that opens the door to baking delicious sourdough breads.

Why do we say that the pedigree of your sourdough starter isn’t important? Our answer is that a long-lived levain will almost certainly change in composition over time. Think of it like a city; a great city may be just as grand two centuries from now as it is today, but it will have different inhabitants—some descended from the original residents and others who will arrive later. Overall, the pedigree of your levain isn’t important. As long as the levain is fed on the same schedule and kept at about the same temperature and level of hydration, it will ripen and mature as expected.

We’ve found that the following flours work best for a sourdough starter: bread flour; all-purpose flour; light, medium, or dark rye flour; 100% whole wheat flour; or a combination of these. We don’t recommend using high-gluten flours (essentially anything with more than 11%–13% of protein), as they contain less starch—the source of the simple sugars yeast and lactic acid bacteria (LAB) feed on. Rye sourdough starters need an additional 20% water due to the thirsty nature of rye flour.

Regular feedings of your sourdough starter will progressively strengthen the lactic and acetic acid flavors, with the souring process leveling off after around 10 days. For a stronger metabolism and more depth of flavor, feed your sourdough starter twice a day.

If you’re looking to learn more about the sourdough starter—such as what feeding and caring looks like, top tips to keep your starter alive and thriving, and more—then check out our free online sourdough course at the Modernist Bread School.