Home milling and flour storage

This post may belong in food storage, but since it mostly concerns flour storage, I posted it here.

So I do not have a flour mill, but I have used them on occasion and also a vitamix. Because the mills I used belonged to others, I would try to mill a lot of flour for multiple  uses. Of course that creates a storage problem. Freshly milled flour contains fat. Commercial processors remove the fat, which allows shelf storage without the worry of rancidity. I used to store my flour in the freezer. Then I was given a vacuum sealer with a jar sealer attachment.  

Vacuum sealing allows you to remove most of the air from a jar, preventing oxidation, which creates rancidity or other spoilage. Dry goods can be stored in a vacuum indefinitely, freeing up space in your freezer. But storing powdered materials in vacuum jars is problematic. If you fill a jar with flour and draw a vacuum, you will see horizontal cracks forming where the air is trying to escape, but is being blocked by the material above.  Eventually the air finds a path and the cracks collapse. This creates a cloud of powder at the top which gets into the seal, and eventually compromises the vacuum. On a vacuum sealed jar, the lid gasket must be smooth and free of dust or grit, or it will slowly loose vacuum. Sometimes over a period of a month or more.

I came up with a method to prevent this cloud from dusting my gaskets:

Fill your jar with flour.
Tamp the flour by banging the jar on a hard surface that won't break glass, such as wood.
Take a chopstick or wood dowel and poke a hole down the center of the flour.
Remove the stick without collapsing the hole you made.
Wipe the rim to remove any flour dust.
Wipe the gasket to remove any dust.
Put the lid on and then the jar sealer attachment, without disturbing the flour.
Vacuum.

If you do this correctly, you will not see any horizontal cracks forming, and no collapse induced dust cloud will flour your gasket  .
In general, I leave the screw ring off my vacuum jars as the vacuum makes them unnecessary. You can periodically test the jars by tapping on the lid. There is a clear difference in the sound that a vacuumed lid makes. The same chopstick (square handle end) can be used to break the seal by putting the square part horizontally between the lip of the lid and the jar threads, and then twisting upward to pry the lid. You will be rewarded with a wooshing sound as the vacuum releases (which will of course dust your gaskets)

That's a good technique. Thanks for the info! What does the hole caused by the chopstick in the middle of the flour do? What size canning jars are you using?

I've mostly shied away from storing flour for all the reasons you pointed out here, and I've recently read that the vitamins in the flour break down rapidly once the grain is milled. Basically, all the "whole wheat" flour on the grocery shelves has still had the good stuff removed so it will last longer and what's left is devoid of nutrients. It's basically white flour with fiber. 😜

My way of approaching it has been to store the grain (which can last a decade or more) until I can process it into flour at the time I would use it. I know mills are expensive, and I don't have one myself yet, but people say the hand crank ones can be found in second hand stores (not around where I live) for cheap. The trade off is obvious. The flour will be coarse and the work will be long and hard.

Then there's investing in a good flour grinder, so it depends on how much you love bread. 😉 And I ❤️ fresh whole wheat bread!

Sorry if it was not clear. The hole creates a path for the air to escape without lifting the flour, thus preventing the horizontal cracks from forming and their inevitable collapse.

For jars, I prefer the wide mouth ones as it is easier to get a good seal on them without having to stack an extra lid on top, and they come in all sizes up to a half gallon.

If the vitamins are breaking down due to oxidation, then this method should help preserve them even better than freezing.

I've decided I'm going to get one of those vacuum sealing thingys for Mason jars. I'll definitely be trying out your technique. I hear the Food Saver is a good one and saw it being used on YouTube. Thanks for sharing your tip!

The first vacuum sealer given to me was a Foodsaver. My friend bought it, and only used it for a couple months, then gave it to me. I found it great for storing meats in the freezer, as the removal of air prevents freezer burn. And of course the jar sealer is great for any dry goods that would go rancid, stale or soggy. I used it for many years until it finally stopped working. Foodsaver makes many models, some better than others. The ones with internal roll storage, sliding cutter, hands free vacuuming and a manual seal override are the best.  I would avoid the vertical ones, as their design seems to waste a lot more bag  material.

Tips:
The small mouth jar sealer does not always work. I found stacking two mason lids together really helps. Although sometimes the second lid gets stuck on the first.
There is a method for reusing food jars of any size as vacuum storage. It involves punching a hole in the lid, covering it with electrical tape, and either a suction cup over the tape, or a vacuum container bigger than the jar.
Some things need to be frozen before vacuuming, to keep the vacuum from crushing them.
Wax paper can be used as a barrier between meat and plastic, but has to be fully thawed to release.
Vacuum things in meal sized portions.
Casserole dishes such as lasagne can be frozen, unmolded from the dish, vacuum sealed, and stored in the freezer. Just put it back in the original dish for baking. I recommend waiting until baking time to add scattered toppings such as shredded cheese.
Periodically tap on your lids to check for loss of vacuum, as the tiniest bit of dust can cause slow leaks.

Enjoy.

Wow! Thanks for sharing this weath of information! I super appreciate it! ❤️❤️❤️

Hi, I'm not sure if anyone is still on here, but if I vacuum sealed fresh milled flour in a jar would it need to be refrigerated or could it be shelf stable at that point? If so for how long?

Fresh milled flour is going to oxidize and turn rancid. Vacuum sealing can prevent that, by removing the air, and with it, the oxygen. It is then shelf stable indefinitely, as far as I can tell. Photodegradation is a thing, but a dark cabinet or colored glass can prevent that.

Vacuum sealing powders can be tricky. As air escapes the flour, it does so in layers which creates dust clouds that will compromise the seal. It's why people put coffee filters or paper towels on top. But poking a hole down the center of the flour, creates a channel for venting, and prevents dust clouds. I use a chopstick or a wooden spoon handle. Any kind of straight thin implement would work.