All of us at some point in time have probably fished an old bag of flour from the depths of the pantry and wondered if it was still okay to use. Flour seems to last forever, but does flour go bad and how can you tell?
The short answer is yes, flour can and will eventually turn rancid. How long it lasts depends on how and where it is stored and what kind of flour it is.
The most common type of flour – general, all-purpose white flour – can last for about a year in the pantry if stored correctly, and indefinitely longer when stored in the fridge or freezer.
Flour Shelf Life & Expiration
Below are general guidelines of how long you can expect different types of flour to last when stored correctly.
- All Purpose Flour, Cake Flour – One year in the pantry. In the fridge or freezer, it can last indefinitely.
- Self-Rising Flour – Four to six months in the pantry, one year in the fridge/freezer.
- Whole Wheat Flour, Rice Flour – One to three months in the pantry. Six to eight months in the fridge. Up to one year in the freezer.
- Oat Flour, Gluten Free Flour, Coconut Flour – Up to three months in the pantry, six to twelve months in fridge/freezer.
- Almond Flour, Barley Flour – Up to three months in the pantry. Up to nine months in the fridge/freezer.
When trying to determine if your flour is still good or not, don’t merely go by the “best by” date. Flour can still be perfectly fresh and usable long after that date has come and gone.
The expected shelf life of flour all depends on how you store it. While best before dates are a handy guide, they mean nothing if your flour is crawling with weevils (flour beetles) within the first few weeks!
Whole grain flours contain more fats and oils than refined white flours. This means that they are more susceptible to oxidization – the process of going “off” – and don’t last as long.
How To Tell If Flour Is Bad Or Expired?
The easiest way to know if your flour has gone bad is to take a whiff. Flour has very little odor (depending on what kind of flour it is), but should smell fresh.
If you get any hint of sour, musty or rancid smells, your flour is most likely already bad. If you’re in a pinch, you can try these substitutes for flour.
Get into the habit of smelling flour every time you use it, so you know what normal is and will more easily pick up when it’s going off.
If you’re still not sure after smelling, take a pinch and put it on your tongue – you will probably pick up a bad taste slightly earlier than a bad smell develops.
It’s more likely that your flour will become infested with weevils or flour beetles long before it turns rancid.
These little bugs are very small – almost invisible to the naked eye – they like to live in dark, warm places and commonly make a home in stored goods in the pantry.
If you suspect you have weevils, you may need a magnifying glass to try and spot the tiny dots. There may be a fine layer of brownish dust over the surface of your flour as a giveaway.
Strangely enough, weevils give of a minty odor when crushed, so try rubbing some flour between your fingers and having a sniff.
The presence of flour beetles doesn’t mean your flour has gone bad – you can sift them and their eggs out, or pop the flour in the freezer for a few days to kill them. It’s up to you if you can stomach the thought of inadvertently eating one or two!
Can Flour Go Bad And Make You Sick?
Eating flour that has turned rancid is not a major health concern and should have no immediate effect on your health.
There is, however, continued research and debate into the effects of mycotoxins on the human body.
Mycotoxins are present in many common food crops, particularly grains – it’s possible they are already present in our flour before it even reaches the supermarket shelves, but if allowed to go rancid, more may develop.
Some research suggests that consuming too many of these mycotoxins can cause health issues later in life such as cancer, kidney damage, and immune system suppression.
From the studies available now, it seems highly unlikely that consuming a small amount of spoiled flour is going to have any serious impact on your short or long-term health.
Unknowingly – or even knowingly – consuming flour infested with flour beetles is not dangerous to your health. In fact, they were considered to be a great extra source of protein back in the pioneering days!
What Happens If You Use Expired Flour?
When generic white flour goes bad, it’s actually the gluten component that turns first.
When you cook with flour that has turned bad, you’re going to lose the qualities that gluten provides; instead of nice stretchy goods that stick together well, you’re going to have a crumbly end result.
If you’re baking products like bread, they won’t rise so high, and if you’re trying to make a cake, it will most likely be flat and chewy. It kind of defeats the purpose of fresh bread.
As for taste, it depends on how far gone your flour is. If it’s only a little bit rancid, it may still taste okay but the texture will suffer. Whereas if it’s really turned, it will definitely be noticeable in your baking, which will taste rather unpleasant.
Different flours degrade at different rates, with higher oil or fat contents turning more rapidly. For example, your almond meal is going to go from a pleasant nutty flavor and aroma to a sour, musty smell more rapidly than a self-raising flour would.
Best Tips To Avoid Rancid Flour
The most important thing to avoid when storing flour is moisture. Expose even the most refined white flour to a damp environment and it will go rancid quick-smart.
The two other considerations are temperature and light. Flour is best stored in a cool, dark area.
As mentioned above in our guide to flour shelf-lives, all types of flour will last longer when stored correctly in the freezer. The next best option is the refrigerator.
However, you can’t just throw an open bag in there and hope it will still be good six months later – the same rules about moisture apply.
For pantry storage, we recommend purchasing some high-quality glass or plastic containers with lids that tightly shut to create an airtight seal. This will protect your flour from creepy crawlies and moisture.
If you’re after a simpler solution and want to take up less room for the fridge or freezer, put your flour into a resealable plastic bag – or better yet, double bag to really ensure no moisture is going to sneak inside to spoil it.
We don’t recommend plastic bags for pantry storage, purely because those pesky flour beetles can and will chew right on through the plastic to get to your delicious flour!
Handy baking hint – if you do store your flour in the fridge or freezer, make sure you let it come up to room temperature before you use it in your baking. If you use it cold, your food might not be as light and airy as you would like.