One of my absolute favorite hobbies is baking, so I wanted to not only share my experience with baking but also discuss the science behind common baking ingredients. We’re going to be exploring five different ingredients: yeast, cream of tartar, butter, baking powder, and baking soda. Let’s get started!
Yeast
Yeast is vital when it comes to creating a hearty loaf of bread, but yeast is incredibly temperamental. When growing yeast for bread, you have to put the yeast in lukewarm water (between 105℉ and 110℉). If the water is too hot, the yeast will die, and if the water is too cold, nothing will happen. Having a good base of yeast is the first step to creating bread, so if you mess up this first step, you might as well start over (Exploratorium, n.d.). Luckily, it usually only takes a few minutes to get the yeast to rise after feeding it some sugar, so you won’t be reset too far.

Cream of Tartar
There’s a fair chance that you might not be familiar with this ingredient, so I’ll gladly explain. According to the McGill Office of Science and Society (2023), cream of tartar is a partially neutralized tartaric acid that is a byproduct of winemaking. Cream of tartar can be used for a number of purposes, but its most important use-case for baking is maintaining structure. My main experience with cream of tartar is when making macarons. You have to create a meringue during the process, and this is where cream of tartar is absolutely necessary. Cream of tartar is what allows egg whites to whip into a firm meringue and not lose its form. Using expired cream of tartar or even none at all will affect how your macarons rise, making them collapse in on themselves. For this reason, cream of tartar is crucial in delicate baking.

Butter
Butter is a prominent ingredient in most baked goods, but something most people don’t realize when they’re using butter is how important the temperature is. You’ve probably read a recipe before where it says something like room temperature or melted or frozen; well, this clarification is very important. The temperature of butter when it’s being combined with other ingredients defines its role as a binding agent at different parts of the process. For example, if butter is melted, it will most likely be a part of the liquids section of a recipe, and if it is room temperature, it will most likely be with the solids. From my experience, frozen butter is usually used to prevent butter from melting too quickly and burning in an oven. All of these temperatures have specific and special roles (McCoy, 2015).

Baking powder
You’ve most likely heard of baking powder or its counterpart, baking soda (which we’ll be talking about next), but you may not know the science behind it. According to Sorangel Rodriguez-Velazquez at American University (n.d.), baking powder is classified as a high quality chemical leavener. Baking powder is activated through moisture and heat and releases gas that moves throughout the baked good, allowing it to expand and grow in the oven. It’s very important to not use too much baking powder because it could cause your baked goods to collapse (Rodriguez-Velazquez, n.d.). Baking powder is pretty crucial to making baked goods like cakes and preventing them from becoming too dense.Â

Baking SodaÂ
Now I know what you’re thinking, what is the difference between baking soda and baking powder? Well for starters, baking soda has only one ingredient, sodium bicarbonate, while baking powder contains that and two acids. The real difference when baking though is that baking soda reacts immediately while baking powder works at different stages, depending on if it’s single or double acting. Both act as leavening agents; however, since baking soda does not have acids built into it, it is only really used when there is some sort of acidic ingredient in it such as cream of tartar or buttermilk (Shipman, 2024). That’s why it’s usually baking soda in recipes involving those ingredients.Â

Baking is such a fun and fascinating scientific process. I hope next time you find yourself baking, you understand the ingredients you are working with better and appreciate the science that goes into every little moment.
References
Exploratorium. (n.d.). Bread Science 101. Exploratorium. https://www.exploratorium.edu/explore/cooking/bread-science
Pellegrinelli, C. (2024). What is Yeast?. The Spruce Eats. https://www.thespruceeats.com/basic-yeast-information-304312
Schwarcz, J. (2017). Cream of Tartar. McGill Office for Science and Society. https://www.mcgill.ca/oss/article/general-science-history/cream-tartar
Greaves, V. (2023). Cream of Tartar: What It Is and How to Use It [Photograph]. All Recipes. https://www.allrecipes.com/article/cream-of-tartar/
McCoy, J. (2015). Beyond Flavor: The Science of Butter. Institute of Culinary Education. https://www.ice.edu/blog/beyond-flavor-science-butter
TWOELLIS. (n.d.). [Photograph of three sticks of butter]. Getty Images. https://www.allrecipes.com/article/salted-vs-unsalted-butter-what-s-the-difference/
Rodriguez-Velazquez, S. (n.d.). 5.5: Baking Powder. American University. https://chem.libretexts.org/Bookshelves/Biological_Chemistry/Chemistry_of_Cooking_(Rodriguez-Velazquez)/05%3A_Leavening_Agents/5.05%3A_Baking_Powder
Shipman, M. (2014). The difference between baking soda and baking powder. North Carolina State University. https://phys.org/news/2014-05-difference-soda-powder.html
Berkheiser, K. & Richter, A. (2023). What’s the Difference Between Baking Soda and Baking Powder?. Healthline. https://www.healthline.com/nutrition/baking-soda-vs-baking-powder#:~:text=When%20to%20use%20which%20one,needed%20to%20produce%20carbon%20dioxide.
Light, J. (2024). Science of Baking Cover Art. STEMComm.