Flour is a staple in the kitchen, used in everything from baked goods to sauces. No matter what types of flour you have on hand, it's essential to store flour properly so it stays fresh. Although there's not much you can do if your flour has already gone bad or sprouted flour bugs (or weevils), a few simple steps will help to prevent these maladies.
How to Store Flour
Most often, flour comes in paper bags and it's easy to simply place it in the pantry when you get home from the store. If you want it to last as long as it should—and avoid opening it up only to find flour bugs—take some time to prepare it for storage. All you need are sturdy, food-grade plastic bags, a fine-mesh sifter, food-grade containers with lids, your freezer, and a cool, dark spot.
- Place the container or bag of flour in a strong, food-grade plastic bag.
- Remove excess air from the bag and seal it tightly.
- Freeze the flour for two days to kill off potential weevils or insect eggs in the flour.
- Remove it from the freezer and sift the flour into a food-grade plastic container with a tight-fitting lid. Label the container with the expiration date or sell-by date.
- Keep in a cool, dark place to prevent other insects from getting in the flour and to prevent sunlight and moisture exposure. Alternatively, keep it in the fridge if you're unsure that your cupboard is cool enough.
The bugs found in flour and other grains are called weevils. If they're present in your flour, the eggs are easily noticeable as a brown surface on the top of the flour when you open the bag. It's most likely that the eggs were there before you purchased it because female weevils lay them inside the grain kernel, and they hatch between one and five months later.
If you're unsure, rub some of the brownish flour between your fingers. If you catch a minty odor, that's the bugs. You can also tightly pack some flour up to the rim of a glass and make a flat surface with the help of a knife. Leave the flour exposed to sunlight for a few hours. If the tight surface looks broken, that's a sign of flour bugs.
Bug-infested flour should be thrown out immediately. Chances are high that almost everyone has consumed flour bugs at some point, as they are not harmful to ingest. However, disposing of the flour with bugs will prevent them from infesting other food in your kitchen or pantry. They're voracious little creatures and will even get into plastic bags, including packaged cereals and rice.
Flour Expiration Dates
How long flour will last depends on the type of flour and the storage conditions. All flours should be stored in an airtight, sealed container. Follow these general guidelines and check your flour regularly for freshness:
- Refined flour: Such as pastry or self-rising flour. It will keep fresh for up to two years in an airtight container stored in a cool place. Refined flour will smell sour when past their prime.
- Nut or seed flour: Such as almond, flax, and hemp flour. Preferably, these flours should be stored in an airtight container the freezer where they can last up to a year. Stored in the fridge, they should last for several months. If the flour has a burnt or bitter taste, that means it's spoiled.
- Whole-grain flour: Such as wheat, spelt, or barley flour. These flours have just three to six months of shelf life. Keep them in an airtight container the fridge and check the expiration date before using. If you catch a funny smell, then it's time to discard the flour.
When exposed to air and moisture, whole grain flours oxidize and produce a rancid smell. Over time, inadequate storage will affect the freshness of your flour, which can affect the result of your baking and maybe even make you sick. If your flour already smells musty or off-putting, it's time to toss it.