These Two Baking Tins Look Alike. Your Batter Knows the Difference.
Food
Baking soda releases gas when it reacts with an acidic ingredient, such as buttermilk. Baking powder includes its own acid components. Double-acting powder releases some gas as the batter is mixed and more as it heats.
Read the recipe before swapping the two. Changing which leavener you use can affect rise, color and flavor, because the amounts and acid balance differ.
Store both containers tightly closed in a dry cupboard. Take a moment to read the label as you measure, especially when the tins sit side by side.