Does Flour Spoil?

You are all set to bake. You reach into your pantry and grab a bag of flour but it looks a little old. You have to wonder, does flour go bad? It is a valid concern and something most bakers come across one time or another. While many believe that flour will go on forever, unfortunately, the shelf life of flour is shorter than you think, and the answer is yes, flour can go bad!

Here’s where things get a bit complicated. You are most likely to find nothing wrong with your flour when you look at it, as it will take some time for it to get moldy, and if you use a container to store your flour, you will not be able to see any expiry date. 

How to Tell if Flour Has Gone Bad

If you think that flour, primarily being a single ingredient, will not spoil and last for years, think again. The old bag of flour you have had for over a few years should likely go into the trash and not in your oven! Here’s how you can tell when your flour has gone bad.

Stop and Smell the Flour

The first thing you should look for when inspecting a package of flour is rancidification. Flour has an unpleasant smell if exposed to air, water, or light for long periods. If the product changes its smell, it is probably stale. Smelling the flour is an excellent way to check if it has gone bad. While the smell of flour varies, it is generally neutral. If the odor is sour, rancid, or musty, then you’re probably dealing with bad dough.

Check the Color 

You can check the color of the flour by spreading it over a bowl. If it is yellowish or pale yellow, it’s probably infested with weevils. These are small insects that live inside flour, and you may not see them at first, but if you spread the flour and look closely, they are easy to spot. If you consume flour with weevils in it, there is no need to panic as these insects are completely harmless. However, no one wants to eat anything with bugs in it, so as soon as your spot the weevils, it’s time to throw the flour.

Check the Expiration Date

This one is obvious but one thing that most bakers miss! If you are shifting flour from a bag to a container, make sure to note the expiry date and write it down. Generally, flours tend to last way beyond the expiry date, but the right thing to do is discard your flour when it has long expired, regardless of seeing any other sign of it going bad. 

How Long Does Flour Last?

How long will flour last depends on the types of flour, and there are more than a few, so you will need to know each class to determine the flour shelf life.  

All-Purpose Flour

The all-purpose flour typically lasts for the longest. It has a shelf life of one year at room temperature, and if you refrigerate it, you can store it for up to two years. However, on the flip side – of all the flours, the all-purpose flour is highly processed and the least wholesome flours health-wise.

Whole Grain Flour

Typically, whole grain flours are more likely to spoil the quickest. One of the main reasons is that the barn layer in grain flour is broken and fully exposed to oxygen. You can store whole grain flour for 1 to 3 months in airtight containers in your pantry. Frozen whole grain flour will last for 2 to 6 months.

Gluten-Free Flour

You can store gluten-free flour in your pantry for up to 2 months. You can refrigerate the flour, maintaining its taste and freshness for 4-6 months. You can freeze the flour for one year, and it is good to use. 

Self-Rising Flour

You can store self-rising flour for up to six months in your pantry, or you can freeze it for up to a year.

Bread Flour

You can store bread flour in a pantry for six months, and you can keep it in a fridge or freezer for a year. 

White Flour

White flour has lower fat content, so its shelf life is longer than whole-wheat and other varieties. At room temperature, white flour will retain its quality for a year. In addition, white flour will stay fresh in a freeze for up to 2 years.

Is it Okay to Use Expired Flour?

Is it okay to use anything beyond its expiry? Probably not, and the same goes for flour(though generally, people continue to use flour after its expiry.) You may have been using flour in your pantry for a real long time and missed the expiry by a long shot! Now what? Well, the good news is unless you sense a foul smell in the flour or the baked good tasted terrible, there are no severe consequences. 

Can Old Flour Make You Sick?

There are certain situations where an expired flour can mean trouble! For instance, expired flour may contain the toxic compound Mycotoxins that come from mold, and eating flour with mycotoxins can make you sick. However, if the flour does have mycotoxins, it will have a strong odor that is hard to miss! 

Why take a risk? If you’re baking with expired flour, it can be unsafe. So it is better to throw it out rather than risk your health for your flour.

What Bacteria is in Raw Flour?

Does flour go bad? Well, if you eat raw flour, you run the risk of picking up a disease-causing pathogen. E. coli is the most common bacteria found in raw flour. The symptoms of an E. coli infection can vary widely, but you’ll experience diarrhea, stomach cramps, or blood in the stool in most cases. Raw flour may also have other harmful bacteria like Salmonella. If you consume too much raw flour, you can develop E. coli and Salmonella infections.

Does Baking Flour Kill Bacteria?

Although it’s not entirely proven that baking flour kills bacteria, experts recommend that spreading flour on a baking sheet and then heating flour in an oven can eliminate any potential pathogens in the flour. According to most chefs, the best way to deal with bacteria or any potential foodborne pathogens in flour is to heat the flour between 160 to 165 degrees.

Can You Kill Bacteria in Flour By Microwaving?

You will find many experts, food bloggers, or chefs recommending heating flour in the microwave at a specific temperature to kill the pathogens in the flour. According to chefs, you need to heat the flour for 30 seconds, mix it and continue to take it to the microwave until the flour is 165°F throughout. Going by popular opinion, this is one of the best and easiest ways to get rid of bacteria. But unfortunately, it is more of a suggestion from experts rather than facts backed by scientific validation. Still, most people prefer to heat-treat the flour in the microwave or the oven.

Heat-Treated Flour

According to some chefs or food experts, using heat-treated flour is a way to reduce the risk of foodborne illness, and it is also important for food safety. This is because raw flour can contain harmful bacteria and germs, and the heating process reduces the risk of diseases. Due to this reason, it is not uncommon to see people sterilize flour by baking or microwaving it before using it in any mix.

Scientifically, heating or baking flour does not guarantee that all the foodborne pathogens will be eliminated and the flour will be safe to consume. Therefore, food scientists have long argued on the effectiveness of this method as it holds no scientific assurance or proof that it works. According to nutrition scientists, there is still much to study regarding the heat-treated process and its effectiveness. For instance, scientists have yet to establish and confirm how long you have to heat the flour to ensure it is bacteria-free and safe to consume.