Amylases: The Enzymes That Break Down Starch in Sourdough Bread

Amylases are natural enzymes that break down starches in flour into simpler sugars. These sugars feed the wild yeasts and lactic acid bacteria during sourdough fermentation. As a result, amylases play a key role in dough development, flavour, and crust colour.

How Amylases Work in Sourdough Fermentation

There are two main types of amylases:

• Alpha-amylase breaks long starch chains into smaller pieces
• Beta-amylase converts those pieces into simple sugars like maltose

These enzymes occur naturally in flour, but their activity depends on factors like grain variety, sprouting, and milling. During fermentation, the sugars released by amylase action help the sourdough starter thrive and support a balanced rise.

The Role of Amylases in Baking

Amylases improve dough texture and boost oven spring. By converting starch into sugars, they also support the Maillard reaction. This reaction is what gives sourdough bread its golden crust and complex flavour.

At The Sourdough School, we teach students how enzyme activity affects baking outcomes. For example, we show how flour made from sprouted or freshly milled grains often contains more active amylases, changing how the dough behaves.

We also explore this in our 3-day BALM workshops, where students use our botanical blend flours and learn how flour selection shapes both flavour and digestion.