- How long does an unopened package of baking powder last? The precise answer depends to a large extent on storage conditions -to maximize the shelf life of unopened baking powder store in a cool, dry area.
Properly stored, an unopened package of baking powder will generally stay at best quality for about 18 months.
Is unopened baking powder safe to use after the "expiration" date on the package? Yes, provided it is properly stored and the package is undamaged - commercially packaged baking powder will typically carry a " Best By," "Best if Used By," "Best Before", or "Best When Used By" date but this is not a safety date, it is the manufacturer's estimate of how long the baking powder will remain at peak quality.
How can you tell whether baking powder is still good to use? To test whether baking powder is still potent enough to be effective: add one teaspoon of baking powder to one-third cup of hot water - if mixture bubbles, the baking powder is still potent enough to use.
Sources: For details about data sources used for food storage information, please click here