What Is a Levain (and Why Sourdough Recipes Use It)

If you’ve been baking sourdough for a while, you’ve probably seen recipes that call for a levain instead of simply “active starter.” While the two are related, they are not the same thing—and understanding the difference gives you much more control over your bread.

Levain = Leaven

Levain is French for leaven. In sourdough baking, it refers to a specifically prepared and fermented mixture that is built for one batch of dough.

At Sourdough University, we teach this same concept but often use the term active starter instead of levain to reduce confusion while students are learning the process.

A levain is made from:

• A portion of your main starter

• Fresh flour

• Water

Once mixed, it ferments for a set amount of time before being added to your dough.

Levain vs. Starter: What’s the Difference?

Your starter is your ongoing culture—the living foundation you maintain, feed, and keep alive long-term.

Your levain is a temporary build, created from that starter, designed to behave a certain way for a specific bake.

Think of it this way:

• Your starter is the mother culture

• Your levain is a custom blend for today’s bread

Why Use a Levain?

Using a levain allows you to control key aspects of your bake, including:

• Flavor development

• Fermentation speed

• Dough strength

• Final crumb and texture

By adjusting the ratio of starter, flour, and water, you can create levains that ferment faster or slower, taste milder or tangier, and support different bread styles.

Different Ratios, Different Results

There is no single “correct” levain ratio. Different breads benefit from different builds:

• Some levains are young and mild

• Others are mature and flavorful

• Some emphasize strength

• Others prioritize extensibility

This is why many artisan recipes specify a levain build instead of simply calling for starter—it creates predictability and consistency in the final loaf.

The Takeaway

A levain isn’t extra work—it’s a tool.

Once you understand that a levain is simply a purpose-built extension of your starter, sourdough recipes start to make more sense, and fermentation becomes far less mysterious.

Learning to build and read a levain is one of the biggest steps toward confident, consistent sourdough baking.

Happy baking from all of us at Sourdough University 🥖