Tests were conducted on baking powder shelf life between 2004-2007 by the Department of Nutrition, Dietetics and Food Science, Brigham Young University. The following are excerpts from the test reports
- “Baking powder is widely used to leaven baked products. The industry standard for baking powder shelf life is eighteen to twenty-four months, but little information has been available on baking powder functionality when stored beyond this time.”
- “The objective of this research was to determine the effect of long-term storage on baking powder functionality. Six samples of double-acting baking powder in original commercial packaging were obtained from donors and two fresh samples were purchased. Samples ranged in age from 0.25-29 years and were stored in cool (15-25 ºC) and dry conditions. Biscuits were made following standardized procedures and measured for height, diameter, and surface crumb color.”
- “Under optimal storage conditions, it appears that baking powder retains its functionality as a leavening agent for many years and can be included in applications requiring long-term food storage”. Here is a link to the complete test report. http://contentdm.lib.byu.edu/cdm/ref/collection/IR/id/77
Once the container is opened the baking powder shelf life is reduced to about 18 months. Moisture in the air will cause the baking powder to react slowly, releasing some of its leavening ability over a period of time.
Baking powder is easy to test for functionality. It is activated by a combination of heat and moisture. Test your baking powder by mixing 1 teaspoon of baking powder with 1/3 cup hot water. Fresh baking powder should produce lots of carbon dioxide bubbles. Cold water will not work for this test, use warm or hot water. The more bubbles the fresher the baking powder.
Remember even if the baking powder shelf life of the unopened can is many years if still pays to rotate your cans periodically. As with any food, store the cans in a cool dry area.