The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

How long will unground flour store?

goer's picture

How long will unground flour store?

Found this on milling site.

"Countless essential vitamins and oils are lost in today's commercially processed flours...all in the name of convenience. To ensure that today's store bought flour will last on shelves, all traces of the grains bran and germ must be removed. Why must they be removed? Because once the bran and germ are milled, they can only last up to 72 hours at room temperature before going rancid."

If grinding gives you 72 hours, just wondering how not grinding effects storage.

proth5's picture

mightily the agenda of the author of your quote.  Yes, whole grain flour will go rancid, and yes, I'm sure certain nutrients begin to degrade the very moment the wheat berry is breached, but "rancid" in 72 hours is pushing it a bit, to say the least.

Anyway, the "unground flour" - or as most of us like to call it "grain" is the perfect little storage container for the goodness within.  Kept cool and  dry and out of the reach of tiny livestock, it will store its goodness for many years.

Hope this helps.

goer's picture

Thanks proth5. I used a poor combination of words. Grain is what it is. You mentioned agenda and it clicked. They want to sell mills not facts. Your info is more helpful. Grain stores a long time evidently. All I need to know.

barryvabeach's picture

Even when it is milled,  it won't go rancid quickly if stored in the freezer or fridge.  I keep my milled flour in bags in the freezer and usually mill once a week and use it all week long with no problem.  

hutchndi's picture

I grind only enough for a few bakes, (my bakes being 1- 2 weeks apart) and store it in a ziplock bag in the crisper in the fridge. So far the improved flavour of using fresh ground flour versus store bought does not diminish for me this way, so if milling once a week I doubt the freezer is necessary, at least to keep the oils from getting "rancid" or off tasting. I know some people prefer to store in the freezer, but I have always been curious as to what freezing might actually do to the properties of the flour.

I only use the fresh ground for a portion of my bread dough mix, so someone who bakes with 100% might have a better idea of how freezing might affect the flour if it does at all.

flournwater's picture

Rancidity generally infers an undesirable resulting from decaying fats and oils.  I would disagree that flour will go "rancid" in 72 hours.  It may degrade to some extent but, "rancid"?   I don't think so.

In my opinion, the veracity of the author's point of view is apparent in the subject line; "How Long Will Unground Flour Store"?

If it ain't ground, it ain't flour.

nhtom's picture

Archeologists found wheat grains in the pyramids.  The grain had been there for perhaps thousands of years.  Kept dry and out of the elements.

It sprouted.

'Nuf said.

Miller1's picture

As has been pointed out by others grain in and of itself if properly stored will last years.  As for flour as soon as the bran layer is cracked you do begin enzomatic activity that over time will cause the flour to become stale.  The only grain I am aware of that will go rancid within 72 hours are hulled oats.  Once the hulled is removed from the oat exposing the groat they can go rancid quite fast and in fact if the temp is warm 72 hours is not out of the question.  Therefore almost all oat groats on the market are cured or stabilized by either steaming them or kiln drying them. 

In fact when it comes to whole grain flours many Artisan bakers prefer some age on their flours while others like it fresh off the mills.  It's really a matter of preference

Mini Oven's picture
Mini Oven

but had no idea it was so quickly done after the hulling process.  Thank you.  I would also like to thank you for other comments made about milling and sifting.  It's great to have your input.  Welcome to TFL.

Would "rolled oats" be steamed and rolled or rolled first and then steamed?  Does it matter?  Is steaming part of the rolling process or is the grain just so soft they can be flattened anytime before/after steaming or drying?

Mini (with roots in SW WI)  

flourgirl51's picture

Mini- commercial rolled oats are steamed and dried and they continue to oxidize after this process is done. This is done to keep them " fresh" on the shelf. I make my own rolled oats using organic dehulled oats in my grain flaker. You simply put the dehulled oats into the flaker and in an instant have rolled oats. I also do this with spelt, rye and wheat grains. The taste is so much better than store bought rolled grains.

Miller1's picture

Flour girl 51  is right if you want to flake oats at home like she suggest you certainly can do that.  In commercial rolled oat meal production the groats are generally steam to soften them to eliminate the "fines" small particles breaking off.  Here is how oat production goes.  First you hull the oat giving you the "oat groat" to make "old fashion rolled oats The company will steam and roll the whole oat groat.  Depending on the thickness of the flake you can produce various products like "Thick rolled oats" "Regular rolled oats" or what have you. Then there is the process of "steel cutting" This is where they take the whole oat groat and chop it into pieces using a "steel cutter" This produces what is most commonly known as "Irish oatmeal" or of course "Steel cut oat groats"  At the mill these steel cut pieces can be separated by size and they use a certain size range to produce "Quick cooking oats"  They steam the steel cut groat and then roll that into a flake which is thinner and smaller then "Old Fashion" or "Regular Rolled oats" by definition quick cooking means 2 minutes in boiling water where old fashions or thick rolled oats can take 5 minutes or more.  Further processing the smallest parts of the steel cut oat groats produces "Baby rolled oat flakes" or "instant oat flakes"  So if you can separate particale size at home using various sieves you could actually flake your own quick oats or instant oat flakes as well.  Just buy steel cut oat groats and separate them

Darxus's picture

Unground wheat berries (unground whole wheat flour) seem to be the most popular staple among people interested in long term food storage.  It will "sustain life" after 30 years of storage, if oxygen has been removed, by means of oxygen removers (iron) or displacement using dry ice (carbon dioxide), according to a Mormon / LDS study (I'm not one, but their knowledge of the subject interests me).  A link to a reference won't get through this site's spam filter.  I think I read that the vitamins are mostly gone by 5 years, but the rest of the nutrition (carbohydrates, protein) is still there. 

subfuscpersona's picture

Whole wheat flour does not become rancid in 72 hours. I am bewildered why this myth refuses to die. I've been milling my own whole wheat flour for over 25 years and base my opinion on my experience baking with home milled wheat.

You don't have to believe me. But would you believe the Washington State University extension program? Here's a quote from

Whole-wheat flour will only keep at room temperature 1 - 3 months. The oils flound in the germ of whole-wheat flour will turn rancid at room temperature...If you plan to store your flour longer, keep it in the refrigerator in an airtight container...Whole-wheat flour will keep for six months in the refrigerator and up to 12 months in the freezer.

While wikipedia is not the last word on every topic, here's what they have to say (source )

An important problem of the industrial revolution was the preservation of flour. Transportation distances and a relatively slow distribution system collided with natural shelf life. The reason for the limited shelf life is the fatty acids of the germ, which react from the moment they are exposed to oxygen. This occurs when grain is milled; the fatty acids oxidize and flour starts to become rancid. Depending on climate and grain quality, this process takes six to nine months. In the late 19th century, this process was too short for an industrial production and distribution cycle. As vitamins, micro nutrients and amino acids were completely or relatively unknown in the late 19th century, removing the germ was a brilliant solution
flourgirl51's picture

I have also been grinding my own grains for years and totally agree with this.