Sourdough

Kathryn Stamm / Sun News Editor

April 27, 2020

Making Sourdough Bread During Quarantine? Here’s the Science Behind It

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People have kept themselves busy during quarantine through doing TikTok dances, making whipped coffee and completing puzzles.

Another activity that has become popular during the pandemic is making sourdough bread from scratch, since it can be time killing and entertaining.

Prof. Keith Perry, integrative plant science, who researches plant viruses and plant diseases, explained the microbiology behind making sourdough bread.

Sourdough is one of many foods that is made through the process of fermentation.

“In a classical sense, [fermentation] is metabolism in the absence of oxygen. In a more colloquial sense, it’s the activities of the microorganisms acting on a substrate or food material and converting it to products,” Perry said.

As there are many foods and beverages that are fermented, like kombucha and tempeh, Perry explained how fermentation occurs in bread.

“You have a community of microorganisms essentially growing on the flour… and the flour consists of a complex of carbohydrates, proteins, and fats. The microorganisms convert those general products to energy so they can grow, and in doing so, they modify the composition and consistency of the flour,” Perry said.

Sourdough Interior

So how does one make their own sourdough bread at home?

“The starting point is called a starter … it’s a mixture of flour and water, in which we’re growing the microorganisms that form the sourdough microbial community,” Perry said. “In its basic form, it’s a mixing of that starter with water, flour, and salt — traditionally wheat flour. Then, the mixture is mechanically mixed or traditionally kneaded by hand to give rise to the desired texture.”

Due to the fermentation process, sourdough bread is unique compared to non-fermented breads.

“[Yeast] acts as a leavening agent which allows the [non-fermented] bread to rise. The big difference is that with the sourdough, you have a more complex community as opposed to a single yeast, and you get a variety of flavors… in short, the difference would be flavor,” Perry said.

Because flavor is a major factor in how the final product turns out, Perry emphasized the importance of using a sourdough culture that works well — the starter should have enough time to ferment and produce natural gases that can leaven the bread.

This process doesn’t have to turn out perfectly, but it’s still important to be careful. While the ratio of flour to water or leaving the starter out a little bit longer than expected won’t ruin the process, extremely high temperatures or molding typically indicate that it’s time to remake the starter.

Part of the reason why bread making can be enjoyable is because the process is so flexible, Perry added.

“Breadmaking can be very enjoyable and it can be done to work around one’s daily life schedule. One does not need to organize a day around breadmaking — if you leave it a little longer than recommended, you’ll get a different bread, but it will still be flavorful, enjoyable and rewarding,” Perry said.

Although making sourdough bread seems like a tedious process, it isn’t as complicated as it looks.

“The only thing that can really go wrong in making bread is if you forget to add the salt,” Perry said.