Reader Liam writes to ask whether a baking soda-leavened batter needs to be rushed into the oven as soon as it’s mixed, since that’s what he’s always heard. Another fabulous question. The answer is a rather unsatisfying “it depends”, Liam. A lot of bakers consider baking soda to be something of a chemical one-trick pony. You add it to a wet batter and it reacts, end of story. But that’s not the whole of it. True, if you combine baking soda with plenty of acid à la a baking soda volcano you are going to get a big chemical reaction that will be over almost immediately. However reacting baking soda with acid isn’t the only way to get it to leaven. You can also degrade it by applying heat. Those are two different processes and both of them yield CO2 (among other things). A lot of recipes both react and degrade soda. They call for a little acid in the formula to get a few “seed” bubbles going, but leave the rest unreacted until the batter starts to warm up, at which point the soda degrades and gives off the rest of the gas. Wet soda starts degrading at about 175 degrees Fahrenheit, which is rather convenient for the baker, no?
So to answer the question, in general yes, you should get something you’ve made with soda into the oven fairly promptly, especially if your batter is very liquid, since CO2 bubbles will escape from it quickly. However a very thick batter or a dough (like a soda bread dough) doesn’t need the same speed since any seed bubbles will probably stay put for a while, and anyway there’s probably more CO2 to come!