Disclosure: When you buy through links on our site we may earn a commission. Learn more.

How to Store Flour For The Long Term


Author:
Last Updated: March 10, 2021

Flour is considered a non-perishable food.  However, if you don’t store flour properly, it will go bad.  Here’s what you need to know about flour storage and the best options, including for long-term storage.

Why Flour Goes Bad

Just like any dry food, flour can go bad if it is exposed to oxygen, light, moisture, or insects. If you just leave a bag of flour in your pantry, here are some of the problems which can occur that will make the flour go bad.

Mold: Humidity or temperature fluctuations can cause flour to absorb moisture and eventually start to get moldy.  You’ll be able to smell the mold before you actually see it.

Oxidation: Oxidation occurs when oxygen from the air interacts with nutrients in the flour, causing them to break down.  This is particularly a problem with whole-grain flours.  Oxidation will cause the natural oils in the whole-grains to go rancid.

Insects: Even if you store your flour in air-tight containers, you can still get insects like weevils or moths.

How is that possible?

Because flour often already has insect eggs in it when you buy it.  It can take weeks or months for them to hatch depending on the conditions.  Once they do hatch though, you have an infestation which is very hard to get rid of.

Absorbing Smells: Flour can act like a sponge and absorb the smells of whatever is near it.  Have onions next to your flour?  Then the cake you make with it will have an oniony smell too.  You especially don’t’ want to store flour (or any other food, for that matter!) near chemicals like cleaning products.

Best Ways to Store Flour

Below are several flour storage methods.  If you want to store flour long-term (over 3 months), then the best method is Mylar bags with oxygen absorbers.  No other method is truly reliable for long-term flour storage.

Air-Tight Containers

Shelf Life: Approximately 6-10 months

In its original paper package, flour usually won’t last more than 6 months.  If you remove it from the package and put it into an air-tight container, it can last much longer.

One potential problem is that there might already be insect eggs in the flour when you get it.  It can take weeks or even months for the eggs to hatch.  When they do, you will have a nasty infestation which is hard to get rid of.  Thus it’s smart to take steps to kill insect eggs in the flour before storage, such as by freezing or microwaving it first.

Some good air-tight containers include:

Freezer

Shelf Life: Indefinitely

If you have room in your freezer, freezing flour is a great way to store it.  It will last forever in the freezer, though you should have a plan in case power outages occur.

To use, remove flour from the freezer and let it get to room temperature.  Note that flour can absorb moisture due to condensation while you bring it to room temperature.  To prevent moist flour, keep the flour in its sealed container – the condensation will collect on the container instead of getting into the flour.

Drying Damp Flour:

If the flour gets damp, you can spread it out on a baking sheet and heat it in the oven at about 200F.  If the flour is very damp, you might need to heat for up to an hour to get it dry.  After drying it, sift it to remove any clumps.

Vacuum Sealing

Shelf Life: 1-2 years

The vacuum sealing process removes air from the packaging. The bags are not completely leak-proof; air and humidity will eventually seep through. However, the reduced amount of air means flour stored this way will last much longer.

Vacuum sealing also keeps insects from getting into your flour.  It will NOT kill insect eggs which are already in the flour though.  That’s why many people first take steps to kill insects in dry food before storage.

To store flour with vacuum sealing:

  1. Place the entire bag of flour into a large vacuum sealer bag. You cannot dump the flour directly into the vacuum sealer bag because the particles of flour will get sucked into the machine.
  2. Follow your products instructions to vacuum seal the flour.
  3. Put the sealed flour in the freezer for at least 96 hours. This is to kill any insect eggs which are in the flour.
  4. If you must remove the flour from the freezer but won’t be using it right away, let it come to room temperature before putting it in any other storage container. Otherwise condensation will form.

Buckets, Plastic Containers or Jars with Oxygen Absorbers

Shelf Life: 5+ years

Oxygen absorbers are little packets of iron which trap oxygen.   If you place OA packets into a food-grade plastic container with flour, it will absorb the oxygen in the container and prevent spoilage from oxygenation.  The lack of oxygen also means that insect eggs can’t hatch.

The problem is that most storage containers are not truly air-tight and will eventually leak.  This includes recycled soda bottles as well as food buckets.

Buckets with gasket lids (see on Amazon) are usually better at preventing air leakage, so are a decent option if you need to store a large amount of flour.

Canning jars also tend to be very reliable and you’ll know the oxygen absorbers have worked because the lid will look “sucked down.”  Just be careful to store jars somewhere cool and dark, as heat and light can also cause spoilage.

Read about oxygen absorbers here.

Mylar Bags with Oxygen Absorbers

Shelf Life: 10+ years

If you want to store flour for months, years, or even decades, the best solution is to use oxygen absorbers in sealed Mylar bags.

Mylar bags are made from a metal-like material which is impervious to moisture and oxygen.  By sealing flour in Mylar bags with oxygen absorbers, the flour is completely safe from light, moisture and oxygen.  Even insect eggs can’t hatch because there isn’t oxygen in the packaging.

When stored this way, white flour can last 10-15 years.  Whole-wheat flour can last approximately 10 years this way.

Read about how to store food in Mylar bags.

Dry Canning – Not Recommended

Dry canning is a process where dry foods like flour are put into canning jars with lids and then heated in the oven.  The heat is thought to sterilize the food and create a seal.  Even though canning jars are used, dry canning is NOT the same as water bath canning.

As warned about by NM State University, there are a lot of potential problems with dry canning.

  • There’s no evidence that the process actually sterilizes food
  • The process can trap moisture in the jar.
  • Botulism poisoning could occur if moist food is sealed in an oxygen-less container. This is not an issue with foods that have less than 10% moisture content like flour, but condensation trapped in the jar could mean the flour does get very wet.
  • Jars can sometimes EXPLODE

Because of these issues, Mylar bags with oxygen absorbers are the only acceptable method for storing flour long-term.

Learn

Food Preservation Book
  • Canning
  • Fermenting
  • Root cellaring
  • Mylar bags
  • And more!

DIY Food Preservation Ebook

Want to stockpile your own food but not sure where to start? Download the Ebook.

You’ll learn about the methods you can use at home to store food for up to 25 years.

This is the information you need to build comprehensive food storage for a rainy day.

Buy Now

Leave a comment

  1. So I put my flour in a big trash bag and froze it for about a week. Then I let it sit out on the counter to come back to room temperature. After than I placed the flour in brown paper bags. Taped them shut. Then vacuum sealed those. I did throw in an oxygen absorber between the brown paper sack and the plastic bag. Not sure if I should have put it in the flour. But it sealed everything well and I have a pound of flour vacuum sealed in each bag. Could you guess that would lengthen the time more than 2 years?

    Reply
    • Your flour should last quite a long time like that. 🙂 Obviously I can’t say exactly how long it will last because some things – like if you live somewhere very hot and humid — will decrease shelf life. You should really look into Mylar bags + OAs though. I find it to be less work than dealing with freezing staples, but that’s just my opinion.

      Reply
    • Yes they do! Almost any grain will or can have insect eggs. However, I personally haven’t noticed the problem with cornmeal/polenta as much. It might be because that is usually packaged in plastic whereas many other flours are in paper bags which can easily be penetrated by insects.

      Reply
  2. I put my flour in ziploc bags with oxygen absorbers in each bag, I plan to put the bags in a 5 gallon bucket, the ziploc bags are not full, how do I know if the oxygen absorbers are working?

    Reply
    • Ziploc bags actually aren’t completely airtight. Air leaks in through the seal and through tiny holes in the plastic bag itself. After putting an oxygen absorber into them, the bag might look “sucked down” a bit. But, over time, the air will leak bag into the bag. I know sealing them can seem intimidating, but Mylar bags + oxygen absorbers really are the best way to go for long-term storage of dry goods.

      Reply
    • It will last just as long — but it might not be “self rising” anymore. That’s because the baking soda and/or baking powder that is in self-rising flour can lose its potency after a while in storage.

      Reply
  3. Can you store cornmeal bolted white with absorber in mylar and how long can it last and after sealing it I am not sure if it should be hard or soft and I don’t think it will be like rice that tighten? I stored white flour for two days in freezer that is what most said should I start over?

    Reply
    • You don’t have to. However, if you don’t remove the flour from the original packaging, it won’t fit well in the bag. You’ll end up with lots of extra space in the bag and need to use a lot more oxygen absorbers.

      Reply
    • The 5lb bags of flour fit perfectly in 1 gallon mylar with enough space to add O² absorbers, squeeze excess air out, and seal.

      Reply
  4. So is there any reason to take the flour out of the paper bag it comes in if I was going to do the following..

    1) freeze out the critters first
    2) bring to room temp
    3) slide entire flour bag into a mylar bag, toss in the oyxgen absorber
    4) suck out as much air as possible with food saver attachment and then seal
    5) put Mylar bag into 5-gallon pal

    What I’m looking for is any reason to bother taking the flour out of the original packaging? Leaving it in seems like it will make things a bit easier on the other end.

    Reply
    • You don’t need to bother with freezing the flour if you are packaging it with oxygen absorbers: the critters and their eggs can’t survive without oxygen. You could keep the flour in the original bag. But it won’t fit very well in the Mylar bag: you’ll end up with lots of extra space on the sides of the bag, which means you’d have to use lots more oxygen absorbers to remove that air. So, in theory, you could leave the flour in the bags — I just don’t recommend it. 🙂

      Reply
  5. Does brown rice have botulism if stored with oxygen absorbers. Can it be used to feed dogs safely. Should it just be thrown out. Was put in mylar bags with oxygen absorbers in 2014. What about whole wheat flour also.

    Reply
  6. Thanks for your post!
    I store my flour in food safe buckets with bay leaves thrown into the bucket. Bay leaves will kill bugs.

    Reply
  7. what about putting a piece of dry ice in the bucket and let the dry ice evaporate forcing the oxygen out? let the lid set on top but not sealed.
    Your thoughts please.

    Reply
    • I don’t know enough about this to give an expert opinion. It seems like there is a high likelihood of mistakes though. I personally prefer Mylar bags + O2 absorbers; I can easily check whether the bags is sealed well and, when using O2 absorbers from a reputable company, feel secure that the flour is safe for years.

      Reply
  8. Great article with great content! I’ll have to save this site under my favorites. Great information for anyone looking to store things long term.

    Reply
    • It really doesn’t matter. Mine always go on top though because I try to work fast: I fill the Mylar bags with flour, give them a nice shake to settle the flour, and make sure everything is set up. Only then do I get out the OAs — which means they end up on top.

      Reply
  9. Same as previously said, good info and thanks for being concise. I hate recipes where the author gives her life story before you can find the ingredients.

    Question: Flour, cornmeal and other dry goods. Can I put them in mason jars and seal with vacuum? ( food saver). I do beans and rice this way and others say good for “ up to 20years”. Regina

    Reply
    • It’s weird. Sometimes it will suck in and other times it won’t. It has to do with the nitrogen content of the food and closed package. Nitrogen is another gas found in air. Oxygen absorbers only remove oxygen, not the nitrogen, so the O2 can be completely removed without the bag getting sucked in like with vacuum sealing.

      Reply
  10. Being gluten-intolerant, I would like to store gf flour, but gf flour often uses some brown rice flour in the mix. I’ve read that brown rice does not store well. Does that include brown rice flour? I’m prepared to seal with food saver; place in mylar bag & then into a bucket using high amounts of oxygen absorbers.

    Reply
    • You read correctly. There is a lot of fatty oils in the bran part of brown rice. It’s in the flour too, so will start to go rancid eventually (it should still be fine for years but it’s impossible to get an exact time — heat will make it go bad much faster!).

      I personally would just make my own GF flour mixture using white rice flour and other processed grains. These last a very long time when stored with OAs. I know it’s not the healthiest option but it is safest for long-term storage.

      Reply
  11. Love how to the point you are without wasting a lot of words. One thing about YouTube videos is they talk to much. They take 20 min to tell a 5 min story.
    One last thought in the event of a system crash because they are just printing money could one not let some bugs get into the product as protein? Lol

    Reply
    • yes, you could eat the bugs, but the bugs are getting their protein from the grain product. so it is more efficient and less icky (and less bug poo) to eat the grain, not letting the bugs eat it. if the bugs are already there, then go ahead and eat them if you want. bake your bread and eat with your eyes closed. Lol

      Reply
      • I blend things which have insects in them so I can’t see them (like making awesome pasta sauce from blended pinto beans and tomato sauce). If I can’t see the bugs, it doesn’t gross me out. Ideally the bug-infested product should be cooked; just like meat needs to be cooked, even insects could have some nasty bacteria in them. Unlikely but still possible.

        Reply
    • I know you meant it as a joke, but eating insects is a great source of survival protein. Grasshoppers are easy to raise and can be blended to make “flour”. 😀

      Reply
  12. If I put my rice in food safe buckets and then put it outside when the temp is freezing or below for 2 days, what happens when I bring it back inside the house. Will the rice sweat and ruin the rice? And will heat kill the eggs. Say I put flour in food grade buckets, how hot would it need to get in my garage or on my porch to kill eggs? Also if I heat my flour in the oven to kill the eggs, how deep a pan should I use, oven temp and how long? I have 25 pound paper sacks, can I put the whole bag in the sack in the oven? Ii am looking for a way to kill tbe eggs before putting the flour into 5 gallon buckets without oxygen absorbers.
    ALSO what happens when you move? Say you have flour, rice, beans in 5 gallon buckets and you go from hot to cold or cold to hot, do you have to worry about mold?

    Reply
  13. if your rice is in the buckets (hopefully with as little air space as possible), then freezing it is a good idea. moisture may condense on the outside of the sealed buckets as they are warmed. i’d go for longer/colder, though. bugs can survive ordinary freezing. the colder/longer the better. i’ve heard 10 days at deep-freeze temps. (but don’t quote me on that).

    avoid heat. it takes a lot of heat to kill the bugs, and at those temperatures, the nutrition in the food is also being destroyed. a lot of people like to use bay leaves in the grain to deter bugs . . but i am not sure how effective that is long term; doesn’t hurt to try it though. might also look into food-grade diatomaceous earth.

    if your product is sufficiently dry, you shouldn’t have to worry about mold.
    it is best to avoid swings in temperature, and avoid higher temperatures in general, if you can. these will decrease the shelf life and the nutrition of the product. just do the best you can (that is different for everybody), and try to use and replace (rotate) your stock, to keep it as fresh as possible (and keep your body used to eating what you store).

    keep up the good work!

    Reply
  14. Hi,

    I’ve just purchased a 55lb bag of Caputo 00 Pizza flour. We’ve estimated that we’ll get through the 55lb bag over two years.

    We live in Southern California, which can get quite hot during the summer, sometimes reaching 90° F indoors.

    I like the idea of Mylar Bags + Oxygen Absorbers and was wondering if I need to keep the Mylar bags in an airtight container or not, or would I need to keep the Mylar bags in the freezer?

    In saying all that, do I need to use Mylar bags at all, or would another method be more suitable seems as I don’t need to store it for 5+ years, and I will be using the flour on a weekly/bi-weekly basis?

    Thank you in advance,

    Sophie

    Reply
    • All you need to do is put the flour in sealed mylar bags with oxygen absorbers. There’s no need to put them in the freezer. I would avoid storing any whole-grain flours though in hot temperatures (the natural fats will start to go rancid). Some people do like to put their sealed mylar bags in buckets as protection against physical damage (earthquakes in CA!!). But that’s no really necessary.

      In your case, maybe it makes sense to put some white flour in Mylar bags with O2 absorbers for emergency use. Keep the flour you use regularly in the freezer and rotate through it as needed.

      Reply
  15. Hello there! I just came across your site, and you provided me with exactly the information I was looking for. Thank you. Where do you recommend purchasing Mylar bags and Oxygen Absorbers? TIA Lisa

    Reply
  16. One of your options to storing flour is to vacuum seal the whole bag. Do I need to worry about bugs from the actual flour bags as some other peppers advise not to store with the bags to avoid bugs?

    Reply
    • Dry cereal like Cheerios usually stores really well. Just make sure it isn’t something like granola that has tons of oil in it. That will start going rancid fairly soon.

      Reply
  17. your site is fantastic and you are a wealth of info…thank you!
    is it the same for storing almond flour and coconut flour? mylar with O2? thanks very much!

    Reply

Leave a Comment