Does Baking Soda Actually Expire? Here's How To Know

Baking soda is one pantry (and in some cases, fridge) staple that we take for granted. Not only does it help leaven cakes and baked goods, but it can also be used for all sorts of cleaning and deodorizing tasks, including cleaning the gunk off your oven door and keeping your trash can smelling fresh. But baking soda will only offer these benefits for so long, and what may come as a surprise to many, it does technically expire. 

Baking soda that's flat won't bubble and react, meaning if you add it to a cake recipe, you can expect your baked good to come out flat and dry. You may not get the same effects if you were to use it in a cleaning solution, either. Baking soda will usually stay fresh for about a year and a half from when it was first packaged (not when it was opened). If you aren't good with dates, you can always test your baking soda with a bit of an acidic ingredient, like lemon juice or vinegar. When you add the acidic ingredient, the baking soda should bubble. If it doesn't, it may be because the baking soda has expired — and you need to buy a new box.

We should note here that expired baking soda won't make you sick — it just won't do what you need it to do. So, if you come to a circumstance where you have a recipe and don't have any on hand, rest assured that there are some baking soda substitutions you can use. Baking powder, for example, is made up of baking soda and cream of tartar, so you can add it to your recipe instead. For every teaspoon of baking soda in your recipe, you'll need to spoon in 3 teaspoons of baking powder to make up for its strength. It's worth noting that you should also test your baking powder before making this swap; instead of adding an acidic element, you can test baking powder with a bit of water. Like the baking soda, it should bubble if it's still good.

Alternatively, you can add whipped egg whites to your recipe. This might work for cakes, as it'll add a lofty texture that mimics the bubbly rise of baking soda. However, this hack requires that you sub out liquids, and not all recipes are egg-compatible (like vegan ones), so baking powder is a more reliable substitute.