When you think science, you probably don’t immediately think of cooking, but take a moment, and you can see why the culinary arts are actually an extremely unique science. Cooking is an art that uses the laws of chemistry, physics, mathematics, and even biology on a regular basis — without most chefs even realizing that what they’re doing is science! Breadmaking, in particular, is a window into science in action. Why? It’s all because of what causes the bread to rise.
Bread rises because of what is known as a leavener or a leavening agent. A leavener is the particular ingredient used to make the dough expand. The type of leavener that you use to bake your bread depends on the type of bread that you’re trying to bake. The main types of leavening agents are yeast, baking powder, and baking soda.
Baking soda (sodium bicarbonate to scientists) and baking powder (a combination of sodium bicarbonate and an acid) are used most often in bread recipes that are made quickly, like pancakes, muffins, birthday cakes, and biscuits. These leavening agents work because of a chemical reaction between the alkaline baking soda and an acidic component. Take, for example, a recipe that calls for baking soda and buttermilk as two of the ingredients. In this recipe, the buttermilk is the acidic compound that reacts with the baking soda to produce the gas that we know as carbon dioxide that makes the bread rise. Recipes using baking soda and baking powder are carefully designed to make the dough rise and to provide just the right texture and flavor. Some recipes combine both baking soda and baking powder to neutralize the acidic component, but still allow the dough to rise. Kind of like a science experiment! In fact, you’ve likely seen baking soda used alongside lemon juice or vinegar in your earliest school science experiments to make fun, fizzy reactions.
For breads that require thicker dough, like fresh baked bread from the bakery or a pizza from your favorite pizza place, yeast is used instead of baking soda and baking powder. Yeast is a living organism, and while there are many different species of yeast surrounding us everyday, the kind used in cooking (called baker’s yeast) is a hungry fungus that is dormant until you start adding all of those recipe ingredients.
Warmed liquids like water or milk wake up the yeast, who then start rapidly feeding on the sugars in your recipe. As the yeast eat away, they produce carbon dioxide. And, that flour you added? It interacts with the water in your recipe to create gluten, which makes the dough stretchy and collects the carbon dioxide while you work hard at kneading that dough. All of this allows the dough to slowly, steadily rise. How many times to let the dough rise depends on the recipe and the type of bread, but the yeast eat and eat until the hot temperatures of your oven finally put them to rest.
Bread baking really is like a science class!
If you’re looking for more insight into how a kitchen is like a science lab, be sure to attend our cooking science course this summer at Summer Science Academy. We’ll dive deep into the many ways that cooking and science intersect — and try out our delicious creations along the way!