Baking soda and baking powder are only as good as their freshness when it comes to baking in the kitchen. Used to leaven everything from cakes and biscuits to doughnuts and waffles (like Jackie Kennedy's waffle recipe, which can be found below), they're the ingredients that help a dough rise as it bakes. And like any ingredient, they can lose their effectiveness as they age, and there's nothing worse than having a cake fail because the ingredients weren't any good.
Because they do lose effectiveness with time, it's best to buy both baking soda and powder in small quantities. Store both in sealed containers in a cool, dry place, and label when you've opened them (baking powder can start to lose its effectiveness within a few months of opening).
There are simple ways to test both baking soda and powder for freshness:
- To test baking soda, place a few tablespoons of vinegar in a small dish or measuring cup, then stir in about a teaspoon of soda. The mixture will immediately begin to fizz if the soda is still active; if there's little to no reaction, it's time to buy a new container. (You can still keep the old one in the fridge to help neutralize odors).
- To test baking powder, place a few tablespoons of hot water in a small dish or measuring cup, then stir in about a teaspoon of powder. Like baking soda, the mixture will begin to bubble and fizz if the powder is still active; if there's little to no reaction, it's time to get some more.
Click on the video link to the left of this post for a demonstration.