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May 31 / Marilla Hurst

Baking powder: the final chapter

You may have heard before that it’s a good idea to replace your baking powder after a couple years. But is that really necessary? I put this to the test yesterday when we completed our taste testing journey through the products left to us from Grandma Zollinger’s basement.

Old product (left), new product (right)

Old product (left), new product (right)

According to Wikipedia, “Baking powder is a dry chemical leavening agent, a mixture of a weak alkali and a weak acid, and is used for increasing the volume and lightening the texture of baked goods.” Baking powder is used to help various baked goods like biscuits, pancakes, etc. to raise a bit so they become fluffy rather than flat and dense.

As usual I popped the tops off the cans and took water activity measurements.


Old product=clumpy



New product=light and powdery


Old product (A), new product (B)

As one might expect, the old product was full of clumps while the new product was a fine powder. The older product, A, came in with a reading of .330 aw and the new product read at 0.399 aw, so not too much of a difference there. What’s interesting is that what seems such a small difference in water activity (0.06) actually has quite an effect on a product like baking powder. That just shows how important it is to have an accurate, recently calibrated water activity meter so you can get the most accurate readings possible when testing samples.

Since you can’t really eat straight-up baking powder I decided to make pancakes to test out the properties of the baking powder. I used the recipe my mom makes from scratch which involves frying the pancakes in butter…mmm mm good.

Batter using new baking powder being cooked

Batter using new baking powder being cooked

Batter using old baking powder being cooked

Batter using old baking powder being cooked

My pancake making did not go quite as planned, unfortunately. I was a little unfamiliar with the induction stove top in our new company kitchen, and at the start I only had one pan going that had a hard time getting warm enough.  Fortunately the pan warmed up eventually and I found a couple more pans to finish off the pancakes.

I unfortunately didn’t take many pictures of the pancakes during and after cooking, mostly because things got kind of crazy trying to finish the pancakes before my testers arrived. Both batters looked basically the same, but the difference came once the pancakes had cooked. The pancake batter using older baking powder did not raise much and produced pretty flat, dense little pancakes. On the other hand, the pancake batter using the new baking powder raised and got fluffy like every good pancake should.

Pancakes using old baking powder

Pancakes using old baking powder (sorry I didn’t get a picture of the pancakes using new baking powder. The ones using new powder were more raised)

When I had my testers come in I offered them a plate with pancake A (old powder) and another plate with pancake B (new powder). No pancake syrup, just testing (which I felt a little bad about later…pancakes need syrup!) On the whole, the pancakes basically tasted the same. Some commented that B was better than A or “yummy” or “more ‘pancake-y’  taste” while A was “bland” or “fair”, but on the whole there wasn’t too much discrepancy. While there wasn’t too much of a difference in taste, there was a noticeable difference in texture. Many testers mentioned in some way that A, the pancake using older powder, was “dense” or “flat.” On the other hand, most testers made a comment about the fluffiness of B, the pancake using new powder. Out of 12 participants that made ratings on their papers out of a scale of 1 to 10, 10 gave B a higher score, 1 gave A a higher score, and 1 gave them the same score. A had an average score of 5.2, and B had an average score of 7.9.

As predicted, looks like old baking powder should be replaced so you can have baking powder will have its intended leavening effect in your recipe. If the old stuff was all you had though, you’d be okay. You’d just have a recipe that didn’t raise much and possibly had a slightly blah aftertaste.

I hope you, the reader, have enjoyed reading about our taste tests comparing products with different vintages. At METER we are always interested in the effect water activity has on the shelf life of different products. Join us for future posts about shelf life and water activity, whether it’s about homemade prosciutto or 39-year-old freeze-dried stroganoff.

Download The Food Manufacturer’s Complete Guide to Water Activity—>

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