A white powder does not reveal at a glance what it will do in batter. Baking soda and baking powder have similar names, but they are not the same ingredient. In an American Chemical Society lesson, a mixture of baking soda, cream of tartar (an acidic ingredient) and starch releases gas when water is added; baking soda alone does not produce the same result in that comparison. [1]
The reacting ingredients are baking soda and the acidic component, cream of tartar in this example. The gas produced is carbon dioxide. The ACS historical account explains that trapping this gas in dough or batter creates a lighter structure. We should not picture every grain simply swelling: a gaseous substance forms and takes up space within the preparation. [2]
University of Illinois Extension also explains the term double acting: some gas is produced when wet ingredients are added, and more during heating. This does not mean that every recipe or packet is identical. The same account notes that adding more baking soda does not guarantee a greater rise: its relationship with the other ingredients matters. [3]
An example invented by our editors: imagine two nearly identical recipe cards, one listing baking soda and the other baking powder. Before correcting either, highlight all the ingredients and read the instructions. Our activity suggests no substitutions or new quantities. It asks us to recognise that similar names do not establish identical functions. A short name can conceal a mixture. [1][3]
Another editorial activity begins with a drawing: sketch a cut section of a cake containing small empty spaces. Then add a bowl outside the cake and an arrow indicating transformation. The picture connects a process with a structure rather than counting bubbles in a real recipe. We could not deduce ingredients, quantities or a successful baking result from that drawing alone. [2]
The history collected by the ACS also shows why storing the mixture created a practical problem: the reaction had to wait until it was wanted. In the product developed by Eben Horsford, starch helped keep the mixture dry. For a final reading question, try distinguishing the ingredients that need to react from the ingredient helping to preserve the mixture. Things in the same packet do not necessarily perform the same job. [2]
Take this with youRemember: baking powder is a mixture. Gas comes from a reaction; recognising the ingredients should come before deciding to replace them.
One idea, in simple words
Baking powder helps batter rise by producing a gas. It is not the same as baking soda alone. A mixture described by the American Chemical Society contains baking soda, cream of tartar and starch. Cream of tartar is the acidic ingredient. When water is added, baking soda and cream of tartar react: together they produce carbon dioxide, a gas. [1]
If batter holds the gas, it can become lighter. Consider this example invented by our editors: we add small empty spaces to a drawing of a cake slice. The picture helps us remember bubbles, but it is not a recipe. It does not tell us how much ingredient to use. We should therefore not change a quantity just because two powders look alike. First we read the ingredient name and the recipe instructions. [2][3]
A little discovery to keep
What did you discover?
Read the sources (3)
- Lesson 3.2 — Exploring Baking Powder American Chemical Society · accessed 2 Oct 2026
- Development of Baking Powder American Chemical Society — National Historic Chemical Landmarks · accessed 2 Oct 2026
- Baking soda vs. baking powder University of Illinois Extension — Jenna Smith · accessed 2 Oct 2026
Original writing and illustration made with AI assistance. Our editorial method
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