As we transition from O2 absorbers to mylar bags, don’t think we’re completely done talking about the little iron packets! Like a toothache or a bad episode of 80’s television, they’ll be back around.

People often wonder when to use a mylar bag… when don’t you have to… when is a food-grade bucket good enough… It helps to think in terms of fighting the enemies of food storage. As a refresher, those are heat, humidity, and UV light, and to a lesser degree, other factors such as natural sugar levels.

When you buy the heavier-duty 5.4 mil bags (vs. the 3.5 mil, which aren’t always cheaper), it does a much better job of eliminating light. Obviously, a well-sealed mylar bag will offer protection from water. Heat will most likely be dictated by your choice of storage location. So—why use the bag inside the bucket?

FOREGROUND: new mylar bags. IN THE BOX: a couple of used ones.

It’s simple—plastic leaks. We may not think it does, but it does. When using O2 absorbers in plastic buckets, you’re actually physically eliminating 20-ish % of the gas that makes up the air. This creates a vacuum, which can weaken the bucket, particularly if you’re stacking them up on top of each other. When you use the mylar bag, you’re providing a metal, non-plastic seal that will remain air-tight, while also keeping the air in the bucket itself intact. Hence, the vacuum remains entirely in the bag and not the bucket.

Do I have to use a bucket? No—but you really should. I once helped a friend move, and he had a bunch of peas stored in mylar bags out in a shed. Half the bags had puncture holes (or mice had chewed into them), thereby destroying the food.

Really cheap iron purchased just for mylar sealing.

Mylar seals easily with a flat-iron of the variety that many women (and some men, now-a-days, I’m guessing :-/ ) use on their hair. A household clothing iron works well, too. There is even one feature that some bags come with: a zip-lock (see the article’s main photo.)

When sealing, leave the last little bit unsealed and try to get as much air out as possible. Remember—the O2 absorber will only remove 20-ish % volume. When you check the bag down the road, it being “soft” (not brick-like) is NOT an indicator of a leak. It merely means you had a lot of air in there when you finished sealing. The O2 absorbers will do their job to full capacity regardless of a large overall amount of air in the space.

One last tip: when you seal it, seal at the top. Then, when you need to open, just cut off the sealed portion. That remaining bag should be re-usable for several time, just with less volume. This assumes, of course, that you weren’t using it on a particularly moist or sugary food.

I must once again mention that the inspiration for the article comes from – and no, they aren’t paying me. Go check them out next time you need supplies.

NEXT WEEK: “BUCKETS” o’ fun!!!