Cinnamon powder lasts a long time if stored well. Store your cinnamon powder in an air tight container and keep it in a cool place. A pantry usually works well if it is protected from the heat of the kitchen. If you plan to store your cinnamon powder for a year or more, consider storing it in your freezer. Keep some cinnamon powder in a more convenient spot for current use and put the rest in an air-tight container in the freezer to maintain its freshness longer. You will find that it stays fresh and potent this way. If you need cinnamon powder with particular potency, consider keeping cinnamon sticks on hand and grinding them fresh when you need potent cinnamon. This will ensure that you maximize your cinnamon flavor in your recipes.