Sourdough Myths #1: Is Yeast Bad for You?

One of the most common sourdough myths is the idea that commercial yeast is bad for you. Let’s dig a little deeper.

First, sourdough bread contains yeast too. A sourdough starter is a living culture made up of wild yeast and beneficial bacteria (primarily lactic acid bacteria, if you must know) that occur naturally in the environment — in flour, in the air, and even on surfaces. Commercial yeast, on the other hand, is a single cultivated strain selected because it works quickly and reliably to leaven dough.

So no — commercial yeast itself is not “bad” for you.

The real difference lies in the bread-making process, especially fermentation time.

Commercial yeast breads are typically fermented for a relatively short period — sometimes just a few hours. Naturally leavened sourdough breads, however, often ferment for 18–48 hours. This extended fermentation allows the wild yeast and bacteria to:

• Break down some of the gluten structure

• Predigest certain starches

• Develop organic acids that may support gut health

Because of this longer fermentation, many people find naturally leavened sourdough easier to digest compared to quickly made commercial yeast bread.

It’s also worth noting that some large-scale commercial breads may include additives or preservatives to extend shelf life and maintain texture. In contrast, handmade sourdough often relies simply on flour, water, salt, and time.

As with most food myths, the truth is more nuanced. In short: it’s not about yeast being “good” or “bad.” It’s about fermentation and the bread-making process. At Hudson Valley Breads, we slowly ferment our breads to give you the utmost benefits. (And they taste good too!)