COVID-19’s hottest at-home trend is a STEM lesson in Science, Chemistry and Math

If you look, right now, it’s everywhere: everyone is talking about baking their own bread and other baked goodies. There’s many reasons – it’s not as easy to go to the store to grab a loaf right now, probably first and foremost. But now that people have the time to dedicate to the age-old art of baking bread, they’re remembering what an amazingly tasty and satisfying experience baking can be. 

We have talked before about how the kitchen can be a great place to practice math (especially fractions!). Baking bread, however, is an important lesson for kids in food science and chemistry, too! And that makes baking bread a great impromptu STEM lesson for kids… and a great life skill. 

Baking bread and other traditional baked goods from cakes to cookies requires something called a leavening agent. For these kinds of goods, there are three main leavening agents: Yeast, Baking Soda, and Baking Powder. 

What is the purpose of a leavening agent? Leavening agents add bubbles of carbon dioxide (CO2) to the dough before and during the baking process. Have you ever experimented with a baking soda volcano? The process is much the same, except some of the gas released remains trapped, making our products light, fluffy, and delicious. 

But what is the difference between the types of leavening agents that release CO2, and how do you use them? 

Baking soda – also called sodium bicarbonate, is a salty-tasting white powder. Just like with the volcano experiment, it requires adding a small amount of an acid to release carbon dioxide into the mix. The acid could be vinegar, such as with this delicious chocolate Crazy Cake recipe, but it could also be honey, lemon juice, buttermilk, yogurt, or molasses. Baking soda releases the gas quickly – so any baking that uses baking soda must be done right away. Traditional Irish soda bread is a great quick bread that can be made with baking soda. 

Baking powder – Believe it or not, it’s very closely related to baking soda. Baking powder is baking soda with a powdered acidic component added in (usually Cream of Tartar), which makes it easier to use. Also, unlike baking soda, baking powder is a double-acting agent. Where baking soda releases carbon dioxide right away, baking powder releases some when mixed with liquid, and more when heated. That’s why baking powder is so amazingly good and easy in things like muffins and pancakes made from scratch! 

Yeast – is the last major leavening agent, and the one most people are familiar with in most bread products from pizza dough to tall loaves of sandwich bread. Yeast is a living organism that eats the sugars in the flour and releases carbon dioxide as a by-product 

Unfortunately, the faster, commercial types of yeast that we are familiar with – active dry yeast and instant yeast – are in short supply right now, causing many people to experiment with the age-old technique of harvesting wild yeast to make sourdough bread. Wild yeast is very easy to cultivate, either from fruit or with flour. Baking with sourdough, on the other hand, is a slow process and a bit of an art form that may take some practice to master – but one that most people agree is well worth the trouble, as sourdough bread is unlike anything we are used to eating at the store. 

If you do decide to experiment with cultivating a sourdough starter as an advanced STEM experiment, avoid unnecessary food waste by adding the starter discard to other baking! Adding it to pancake batter during the morning feeding of the family (and starter!) is a great way to use the discard. 

Happy baking!