How To Tell If Your Baking Soda is Old

Do you know how old the baking soda you have in your cabinets is? I don't. Although I bake a lot, I am sure that box has been sitting in the plastic bag for a long time. Remember, you are only using a teaspoon or two at a time. Well here is your test. Pour some white vinegar or lemon juice over a 1/2 teaspoon of baking soda. If it doesn't bubble up - IT IS OLD!