I have a pantry moth problem in my kitchen cupboards and now store all of my flours in the freezer. Will this alter their baking properties?
Whole-grain flours such as rye and wheat contain more fat than refined flours like all-purpose and can turn rancid quickly at room temperature. For this reason, we’ve always recommended storing these flours in the freezer. As long as we bring them up to room temperature before using, this has no ill effects. But we hadn’t tested the effects of freezing on all-purpose flour, so we placed several cups in a zipper-lock bag in the freezer for a few weeks and compared them with all-purpose flour stored in the test kitchen pantry. On testing day, we brought the frozen flour to room temperature, then prepared a yellow cake, brownies, and spritz cookies with both the once-frozen and never-frozen flours.
The results? Tasters found the samples identical. So go ahead and store your all-purpose flour in the freezer. Just use an airtight container, and don’t forget to bring the flour to room temperature before baking. When we skipped this step in the test kitchen, the cold all-purpose flour inhibited rise and yielded denser, chewier baked goods, much as chilled whole-grain flours do. To quickly bring flour to room temperature, spread it in a thin layer on a baking sheet and let sit for about 30 minutes.