The Flour Is About to Expire?
Even if you don’t bake that much, you probably have a bag of flour in your pantry. In addition to bread and other baked goods, processed wheat powder is used as a breading and thickening agent in a wide variety of cuisines. It’s obviously shelf stable – that’s why we keep it on our pantry shelves – but how stable is it and how can we tell if it’s destabilizing?
The short answer is that flour is “good” for 3-8 months at room temperature and pressure, but this can be extended significantly by changing storage conditions. Storing it in the freezer, for example, can extend its life by years, especially if you take care to seal it in an airtight container to prevent odors from entering. (Chilled flour can last up to a year, but I just can’t. There is room in my fridge.)
Some flours spoil more than others. White flour has the longest shelf life due to the way it is processed. The grain and bran are removed, leaving only the starchy endosperm, and the oils live in the grain and bran. Oils are good for you, but they also get rancid, so whole grain flours (or alt flours made with other oily ingredients like almonds) are likely to go bad faster than their highly processed counterparts.
In addition to oils that can turn rancid, moisture is the main factor that accelerates flour evaporation, so store it in an airtight container regardless of storage temperature. Wet flour usually turns into moldy flour quickly, so be careful not to dip damp dishes or scoops into the bag.
If you’ve lost track of how long your flour has been in the pantry, take a look at it and smell it. Look for traces of mold and insects, and sniff anything that smells. Rancid butter has always smelled like crayons, but bad flour can also smell like moldy or sour. Flour itself doesn’t smell that strong, so if you find your brain “trying to detect” a smell, then that smell doesn’t belong to you. Stir in the flour and buy a new bag. (It’s very cheap.)