Does Baking Soda Go Bad?

Baking soda, also known as sodium bicarbonate or bicarbonate of soda, is a pantry staple. It can be used to leaven baked goods like cookies, cakes, and breads, and is an effective and eco-friendly cleaner.

Baking soda is a base (with a pH of 9.5) that reacts with acidic ingredients like vinegar, lemon juice, buttermilk, and cream of tartar to produce carbon dioxide. This is what gives quick breads and batters their rise.

Potent, fast-acting baking soda is key in recipes that call for the ingredient. Otherwise, the necessary chemical reaction won’t take place and you could end up with a flat, stodgy cake.

Does Baking Soda Expire?

Technically, no, baking soda does not expire. Even though containers are often printed with a sell-by or use-by date, this is a ballpark estimate for when baking soda could begin to lose its efficacy. 

The general rule of thumb is: when stored properly, baking soda will last for two to three years sealed in its original container. Once opened, it will keep for at least six months. While baking soda never “goes bad” in a way that would make you sick, at some point it will stop working as well as it should, producing inferior bakes.

How to Tell If Baking Soda Has Gone Bad

If you’re not sure how old your baking soda is, use this test to ensure it still works properly. Even when buying brand new baking soda, it’s a good idea to test it before using. This is because you don’t know how long the package has been on the shelf at the market or how it’s been stored.

Luckily, there’s a quick and easy trick for testing the potency of your baking soda: 

1. Add roughly 1/2 teaspoon of baking soda (no need to measure) to a small bowl. 
2. Add about 1/2 teaspoon of white vinegar or fresh lemon juice (again, no need to measure) to the bowl and watch.
3. The acid and base should react immediately, just like in the classic grade school volcano experiment. If the mixture fizzes and bubbles up aggressively, then the baking soda is in good working order. If it barely fizzes or not at all, toss it. It’s past its prime.

Since the test is so quick and easy and uses such a small amount of vinegar and soda, test your baking soda regularly to ensure baking success every time. Plus, you can pretend you’re a mad scientist!

How to Store Baking Soda So It Stays Fresh

One factor that can speed up baking soda’s decline is improper storage. Store unopened boxes or containers of baking soda in a cool, dry place, like a pantry. Once opened, baking soda should be stored in a sealed container. If yours came in a box, transfer it to a jar or similar container that’s airtight.

Baking soda’s biggest enemy is moisture, so don’t store it in the fridge. While a container can help eliminate odors in the fridge and freezer, don’t be tempted to use your fridge baking soda for baking. It absorbs flavors and can impart unwanted flavors into your baked goods.

Are Baking Soda and Baking Powder the Same Thing?

Baking powder and baking soda should not be used interchangeably in recipes. Baking powder contains baking soda as well as an acidic ingredient like cream of tartar. Once water or another liquid is added, it can produce carbon dioxide all on its own without the need of an additional acidic ingredient.

You cannot swap baking soda and baking powder one to one, since baking soda is much stronger and requires an acidic ingredient. Double check your recipe to make sure you’re using the right leavening for the best results.