Flour seems like one of those ingredients that might last forever. It is dry and it is typically made with a single ingredients so what could possibly spoil?
Well, flour can, in fact, go bad and that bag you have had on your shelf for five years may need to go in the trash! Here are a few ways to tell is your flour has gone bad.
How Long Does Flour Last?
Different kinds of flour have different shelf lives. White, all purpose flour will be able to last longer than any other flour as it is a highly processed, very refined grain.
A grain of wheat consists of three main parts, the germ, the bran and the endosperm. When making white flour, the germ and bran are removed from the grain, leaving behind only the endosperm. This part of the wheat is very dry and contains few nutrients.
Less nutrients and minerals means less aspects of the flour to spoil. That is why white flour will last the longest on the shelf (and also why it is considered to be one of the least beneficial flours health wise).
All purpose flour has a general shelf life of 1 year when stored in a pantry or up to two years when kept in the refrigerator.
Once the germ and bran are left on the wheat, the shelf life decreases tremendously. The fat and fiber, along with many of the other vitamins and minerals, in the less processed wheat will spoil when kept on a shelf for too long.
Whole wheat flour only has a shelf life of one to three months, a significant drop in time when compared to white flour.
Alternative flours also have reduced shelf lives, again because of all the vitamins and minerals in the flour components that have potential to go bad.
Oat flour will last about three months when store in a pantry as will coconut flour, buckwheat flour and other nut flours. You can double the shelf life by storing any flour in the fridge, keeping it in an airtight container as well.
How to Identify Rancid Flour
One way in which your flour can go bad is when the fats and oils in the flour go rancid. This means the fats and oils are too old and should no longer be eaten.
When this happens, there are several ways you will know that the flour, is in fact, rancid.
The main warning sign of rancid flour is the smell. When flour has gone bad, it will smell sour or musty. Normally, flour has no odor at all or just a slight nutty smell.
Yet rancid flour will smell quite strongly, even being described as a rubber scent or similar to play-dough.
If you open your flour jar and immediately smell something off, you will know that your flour is bad.
How to Identify Flour Beetles
In addition to the oils in the flour itself going bad, you also need to watch out for flour beetles, also called weevils.
These are tiny bugs that live inside flour, laying eggs inside the grain. The gees then open up and the small weevils will happily eat the flour until they are full grown and then begin the cycle again.
If you have weevils in your flour, chances are you will see them moving the moment you scoop into the flour. They may not be immediately visible on the flours surface as they tend to burrow into the flour so you will need to push the flour around in order to see them.
While weevils are actually completely harmless if accidentally consumed, no one want bugs in their food! So if your flour has signs of weevils, the best plan is to throw the flour away (however some people recommend just sifting the bugs out in order to keep the flour).
In order to prevent weevils, you should store your flour in an airtight container inside the fridge.
What Happens if You Consume Bad Flour?
If you suspected your flour was bad but used it anyway, what could really happen? What exactly are the side effects of consuming bad flour?
Consuming rancid flour can actually be harmful. When flour goes bad, it starts to contain mycotoxins. While fine in the short term, consuming too many mycotoxins can cause long term health issues like cancer, kidney damage and reproductive disorders.
While you would need to consume a large amount of bad flour for these side effects to really take place, it is better to be safe than sorry! It is best to simply avoid using rancid flour and buy fresh new flour anytime you are wondering about the state of the flour on your shelf.
As I mentioned before, eating flour that had weevils will not harm you at all. Other than being unappetizing, these bugs are nontoxic and won’t have any health effects at all. They will die instantly in the oven and you may not even notice that they are there.
But once again, no one wants to eat a food that has been infested with bugs!
Baking with Bad Flour
If you happen to bake once or twice with rancid flour, you probably will not have any harmful health side effects but your food will definitely suffer. Flour that has gone bad will give your food a sour or musty taste.
Even though the food you made is fresh, it will not smell or taste fresh. The bad flour will transfer its taste directly to whatever you are cooking.
In addition, if you are using a self leavening flour, the leavener in the mix may have also gone bad. Whatever you are trying to leaven will fall flat as the flour is too old for it to function properly.
How to Tell if Your Flour is Bad
Now that you are well aware of the ways in which flour can spoil and the side effects of using bad flour, here are a few tips to help you decide if your flour has, actually gone bad.
1 – Check the Date
There is one simple thing you can always do to instantly see if your flour has gone bad and that is to check the expiration date on the bag of a flour.
Yes! Most flours do have an expiration date printed right on the bag that will tell you how long the flour should last. These dates are typically estimated based on the flour being stored in a dry, cool place.
This doesn’t necessarily have to be a fridge but it should be somewhere that is not very hot or humid.
Of course, to utilize the expiration date as a measure of your flour’s vitality, you will need to keep the bag on hand or write down the expiration date before throwing it away.
2 – Check the Color
The color of a flour should never change. If you have white all purpose flour, it should always be white and fluffy.
If your flour changes color to anything other than it’s original state, it has gone bad. Wheat flour with a yellowish tinge may have bad oil seeping out of the grains. If your corn flour has a blueish hue, it may be starting to grow mold.
A discolored flour is a bad flour!
3 – Give it a Sniff
Rancid flour is very easy to detect if you just smell it. In fact, when you open the flour bag or container, you will likely be hit with a musty, sour smell that clearly indicates the flour is bad.
If you don’t smell anything, get a little closer and give the flour a good sniff. If you still smell nothing, you flour is probably just fine to use! The smell of bad flour is hard to miss.
How to Store Flour
While it is easy to just keep flour in the bag that it came in, rolling the top over and putting it in the pantry, this method really only works if you use your flour frequently.
If you tend to have a bag of flour hanging around for several months, you may want to consider a better method of storage.
First, put the flour in an airtight container (link to Amazon). A plastic or glass container with a tight fitting lid is the best option. Next, place the flour container in the fridge.
Keeping in in a cold place will actually double the shelf life of the flour, preventing any oils from going bad.
In addition, weevils cannot survive in a fridge so there will be no bugs in your flour either! A much better storage idea to increase the life of your flour.
No one wants to have bad flour on their hands, however, if your flour has been sitting around for a while, it may go bad! Now you are well equipped to recognize when flour is bad, know why it has gone bad and you know what to do about it.
Essentially, if the flour is bad, throw it away! You can also just try to make an effort to bake more- everyone could use some more baked goods in their lives!
Sarah is the founder of Baking Kneads, LLC, a blog sharing guides, tips, and recipes for those learning how to bake. Growing up as the daughter of a baker, she spent much of her childhood learning the basics in a local bakery.