Does bread flour expire? Yes, but the time it takes to do so depends on the type of flour, how it is stored and several other factors.
How long do whole grains last?
Grains of wheat stored in the right conditions (think granaries) can last for a year. However, most of us don’t have that in the pantry or the airtight, pest-resistant containers like grain silos.
Intact whole grains like wheat berries and brown rice last up to six months on the average pantry. Store them in the freezer, and it will last up to six months. Exposure to air will shorten this dramatically.
Whole grain amaranth will last four months in the pantry, while barley berries or groats last six months.
How long does wheat flour last?
Grinding up wheat into a powder means it will spoil much faster than intact grains. Because the protective bran has been broken, oxygen can reach it. Most grain flours will last up to three months in an airtight container that’s cool and dry. It could last up to six months in the freezer.
Wheat flour can sit on the shelf up to six months if unopened. Open it at all, and it lasts up to eight months if you refrigerate it immediately. White flour containing preservatives can last as long as a year if the container is unopened.
If you refrigerate it immediately upon opening, and the flour could be used for up to a year as long as it is sealed from the air and humidity inside your fridge.
Self-rising flour is generally good for four to six months in the pantry.
How long do other flours last?
All grains have a shorter shelf life if the protective germ is broken, and it is typically half the life of the unprocessed grain. Amaranth berries last four months in the pantry, while the flour lasts around two months.
If you put amaranth grain in the freezer, it will last up to eight months, whereas the flour will last up to four months frozen. Barley can last six months in the pantry if the germ is intact, but barley flour lasts three months in the pantry.
If you have brown rice, it will last six months in the freezer and three months in the pantry. White rice is worse. Wild rice will last four months in the pantry, but flour made from it may last two months in the freezer.
Potato flour can last up to eight months but is best eaten within six months.
Buckwheat is notably short. It lasts two months in the pantry, while buckwheat flour lasts just one month on the shelf. Freeze the flour, and it could last two months.
Millet is comparable. The berries will last two months in the pantry, while millet flour lasts a month in the best of circumstances. Oats can sit in the pantry for four months, but oat flour is good for only two months.
This is why many people only milled flour shortly before they intended to use it.
Whole-grain rye lasts six months in the pantry and a year in the freezer, but the rye flour only lasts three months in the pantry and six in the freezer. Corn flour can last up to a year in the pantry.
However, it is generally good for six to nine months. Dried corn kernels can last that long, though popcorn tends to last even longer. Yet cornmeal can last for up to two years if properly stored.
How can I make flour last longer?
Store the wheat flour in airtight containers whether it is a plastic bin with a lid, glass container with a mason jar lid or a sealed plastic bag. Ensure that it stored in a container that insects and rodents can’t get into.
Store it in a cool dry place. When you open the container, try to open just a corner of it. Once you get what you need, seal the container. If it is in a plastic bag, fold it over and try to rubber band it together. A clip is second best. You can extend its life by storing it in the fridge. Better yet, store it in the freezer.
Write the expiration date on the container when you put it in the fridge or freezer. And ensure that the container is sealed against moisture. If the container gets damp on the inside, the flour will go bad.
This is why you may want to put an open bag of grain inside another, a larger bag you can completely seal.
If you’re not going to use it for a few months, freeze it immediately. If it is halfway gone, freezing it won’t extend its life by another three to six months. You can add oxygen absorbers to the grain to try to extend its shelf life.
If you have whole berries or other intact whole grain, don’t mill it until you’re ready to use the flour that results from it.
How can you avoid buying expired flour?
Check the expiration date before you buy the grains. If buying from bulk bins, only buy what is turning over quickly. If the grain has been sitting at the bottom of the bin for a month, its shelf life is that much shorter.
How can you tell if grain or grain flour has expired?
Depending on the type of grain, it should either have a slightly sweet scent thanks to the sugars and carbs or no smell at all. If it has a musty smell, it was going bad.
If it has an oily smell, it is rancid and should be avoided. The smell comes from the essential oils in the grain that has spoiled.
Bugs in flour do not necessarily mean that the flour has gone bad. However, they are a sign that it wasn’t stored properly. If you find bugs in the flour, just get rid of it.
We don’t recommend following the classic advice of freezing the bag for a couple of days to kill weevils. In fact, if you find weevils in the flour, you probably want to throw out all the flour in the pantry because if they are in one container, they’re probably in another.
After all, the weevils had to come from somewhere to get into the flour.
Note that flour can harbor bacteria. This is why you should always bake flour before eating it, whether or not it is close to its expiration date.