You’re stuck at home, the store is out of yeast … maybe your favorite bakery is closed or your science teacher has asked you to participate in a real science project at home. Whatever your reason, the science of sourdough bread is super fun!
We all love bread – whether it’s a pita, challah, bagels, roti, naan, focaccia, tortillas or pizza. Bread making begins with two basic ingredients–flour and water. Flour is the powder made by grinding the seeds or kernels of a grain.
Wheat is the most common type of flour, but there are other grains–including barley, rye, oats and buckwheat, which also make flour.
The wheat grain consists of three important parts: the bran, endosperm, and germ—all full of vitamins, minerals, and fiber that make the baked product nutritious and delicious.
One of our favorite breads, sourdough, dates back to 6,000 years ago in Egypt when someone baked the first loaf of bread. Most likely yeast was discovered when someone left some flour and water out in the open air a little bit longer than they meant to. The result—a bubbling mixture of flour and water, and the creation of what we now call sourdough bread!
There are millions of microbes–some good and some bad. COVID-19 is one of the bad ones, but the secret to sourdough success is due to the good, tiny microbes of bacteria and yeast, including lactic acid bacteria (Lactobacillus) and wild yeasts (Saccharomyces and Candida).
Wild yeast and bacteria float around in the air and live on grains and in the flour. When you add water to flour, these microbes feed on the sugars in the flour and multiply. So, with just flour and water, you can create a bubbly mix of microbes. We call this mix a “starter” because it starts the bread-making process. You can keep your starter alive for years.
When microbes eat, they release bubbles of carbon dioxide (C02). These bubbles make bread dough rise and create the holes you sometimes see in slices of bread. When these microbes eat they also produce acids. These acids, lactic and acetic, give the typical sourdough bread the famous and wonderfully sour taste and smell. This process of yeast and bacteria eating sugars in the dough—and then producing gases, acids and alcohols—is fermentation!
First, you create a starter and when your starter has matured, it is time to use the starter in other fun recipes. You might see other names for the sourdough starter such as preferment, levain, poolish and biga. These are just names for other types of sourdoughs.
Experienced bakers find that sourdough bread tastes better after it has had time to cool, which allows the flavors from the flour and fermentation to develop. But, who can resist warm bread straight from the oven?
You can use this sourdough starter in lots of other delicious recipes such as pancakes, muffins and pizza crust!
Time to get baking!