Topic: Preventing grain spoilage by insects

[Pandora]

I'm big on food storage and my hobby is finding and photographing beetles. These two interests converge when grain beetles start reproducing in my stored grain products.   I had bought some 50-lb. bags of corn and oats at the Tractor Supply Company store, intending to treat them for insects and put them up in 5-gallon buckets. I never got around to it and eventually noticed tiny grain weevils showing up around the house. The grain had not only become infested with Rice Weevils but their droppings had produced a lot of ammonia that turned the oak flooring dark beneath the most infested bag. I dumped 200 pounds of grain out on the compost pile, a free feed for birds, mice, and squirrels. Rice weevils are hardly the only grain beetle to worry about.

Here are some of the others, belonging to eight additional beetle families, with links courtesy of the Bug Guide web site: 

    Oryzaephilus mercator - Merchant Grain Beetle
    Oryzaephilus surinamensis - Sawtoothed Grain Beetle
    Cathartus quadricollis - Square-necked Grain Beetle
    Nausibius clavicornis
    Lasioderma serricorne - Cigarette Beetle
    Rhyzopertha dominica
    Latheticus oryzae - Longheaded Flour Beetle
    Cryptolestes ferrugineus - Rusty Grain Beetle
    Tribolium castaneum - Red Flour Beetle
    Thorictodes heydeni
    Tenebrio molitor - Yellow Mealworm
    Tenebrio obscurus - Dark Mealworm
    Typhaea stercorea - Hairy Fungus Beetle
    Symbiotes gibberosus 

In addition there are moths, flies, and small wasps that lay their eggs in grain products, all of which can ruin your stored food supply if precautions aren't taken.   Here are three common alternatives for killing off any grain pests that happen to arrive in bulk grains: 

1. Purge the oxygen with another gas. Buy some dry ice (frozen carbon dioxide) or a tank of CO2. Put a few ounces of dry ice in a container of grain. Cover with lid but wait several hours before sealing. The CO2 is a heavy gas and will slowly fill the airspace from the bottom up, pushing out the ambient air containing oxygen. A faster method is to slowly fill the bucket by inserting a hose from a CO2 tank into the bottom of a filled container and cracking open the valve. Then the container can be sealed right away. 

2. Absorb all the oxygen with O2 absorber packets. (You can also use hand-warmer packets [, although they are much more expensive].) This method is best used with a Mylar liner inside the storage container ([food grade HDPE] plastic bucket, etc.). Once the O2 absorber packet is added, heat-seal the Mylar bag with a clothes iron against a broomstick or other straight stick or rod, then seal the container. 

3. Add a safe-to-eat physical insecticide, food-grade diatomaceous earth, mixing thoroughly with the grain. I use one cup per 100 pounds of grain. This substance is composed largely of the silaceous exoskeletons of diatoms, tiny unicellular aquatic organisms that died over eons and accumulated in deep deposits of ancient lakes and sea beds long since exposed on dry land. Their exoskeletons have sharp edges that scrape off the protective waxy coating on the exoskeleton of grain pests that permits them to survive in dry conditions. They lose moisture too rapidly to replace and they perish, never being able to multiply. A side benefit to this method is that it abrades the protective coating of intestinal roundworms as well -- good survival medicine.

JWR Adds: All three of those methods have proven efficacy. Needless to say, do not be tempted to use any chemical insecticides, since they can be toxic to humans and would also horribly taint the taste of foods. Also, don't think that by merely sealing newly-bought grains or legumes in airtight containers that you will will protect them from infestation. The chances are quite high that they already have insect eggs larvae present.

Link

[Libertas]

Good info!  I will pass it on.

 

[Pandora]

The only thing I've packed for long-term storage is rice - the rest came in #10 cans - and I froze the bags whole before I broke them up.  Freezing as remedy wasn't mentioned, so I hope .....

[Libertas]

But some insects can go into a dormant phase...not sure about bettles & worms but...if thawed out...

 

On the plus side, free protein!

 

[Pandora]

But some insects can go into a dormant phase...not sure about bettles & worms but...if thawed out...

 

On the plus side, free protein!

 

Blech.

I read, somewhere, that freezing would kill them and their eggs, which is why I chose that method.

[Libertas]

Maybe that's true, perhaps these grain-lovers are more fragile.

Thank God!

(I loath pretty much every bug on the planet!)

[Pandora]

After searching around, it seems there are no hard and fast answers to the "freezing" question, *sigh*, one site says 3-4 days, another says 3 weeks.

Plus, I found this which pretty much negates everything written in the SurvivalBlog post except for #2.

I'm going to have to go check my storage now and probably go the mylar/O2 absorber route for the rice, even though we rotate.

[Libertas]

Well he did say freezing can offer peace of mind!  But it is good to learn from someone who's been doing it a long time what they've found through experience.

[John Florida]

Anything on vaccum packing?I'm using it now and hope the lack of air kills and preserves dry goods.

[Pandora]

I haven't seen anything on vacuum packing, although the removal of oxygen is this manner is, IMO, equivalent to mylar bags/oxygen absorber/bucket preparation and storage.

I retrieved some rice for rotation today that was put up in 2/09, prepared for storage by first freezing, then bagging, and storing in 5-gal pails with gamma-seal lids and I'm happy to report it is clean of critters.

The details on our freezing regimen is we froze for at least five days, but not much more; parked on the counter upon removal from the freezer to come to room temp and dry for about three days, and then broke up for bagging and bucketing.

[michelleo]

Anything on vaccum packing?I'm using it now and hope the lack of air kills and preserves dry goods.

Vacuum sealing also removes oxygen from your grains so they don't spoil.  They may not last 10-20 years w/out oxygen absorbers and mylar bags, but I'm sure it's still adding years to the life of the grain.

[John Florida]

Anything on vaccum packing?I'm using it now and hope the lack of air kills and preserves dry goods.

Vacuum sealing also removes oxygen from your grains so they don't spoil.  They may not last 10-20 years w/out oxygen absorbers and mylar bags, but I'm sure it's still adding years to the life of the grain.

 Remember were also trying to re-grow it year to year so you may only need it to last a couple of years.I hope.

[Libertas]

So if we bagged in mylar bags and sealed in pails but did not vacuum seal how long will it last?  If I toss in some oxygen absorbers how much furhter could I extend the shelf life?

[John Florida]

So if we bagged in mylar bags and sealed in pails but did not vacuum seal how long will it last?  If I toss in some oxygen absorbers how much furhter could I extend the shelf life?

 Years! Michelleo posted that it would last 10 to 20 years.

[Libertas]

So if we bagged in mylar bags and sealed in pails but did not vacuum seal how long will it last?  If I toss in some oxygen absorbers how much furhter could I extend the shelf life?

 Years! Michelleo posted that it would last 10 to 20 years.

I can work with that!

[John Florida]

So if we bagged in mylar bags and sealed in pails but did not vacuum seal how long will it last?  If I toss in some oxygen absorbers how much furhter could I extend the shelf life?

 Years! Michelleo posted that it would last 10 to 20 years.

I can work with that!

 Hell yes!!Now where to get 10 year supply if you don't live in a producing state without getting raped.

[Libertas]

So if we bagged in mylar bags and sealed in pails but did not vacuum seal how long will it last?  If I toss in some oxygen absorbers how much furhter could I extend the shelf life?

 Years! Michelleo posted that it would last 10 to 20 years.

I can work with that!

 Hell yes!!Now where to get 10 year supply if you don't live in a producing state without getting raped.

If you find out let me know, as it is I'm walking kind of funny, damn I hate that!

[Pandora]

So if we bagged in mylar bags and sealed in pails but did not vacuum seal how long will it last?  If I toss in some oxygen absorbers how much furhter could I extend the shelf life?

Sealing the oxygen absorbers in the bag and pail (with the grain) provide the same effect, albeit a bit slower.  Over time, the air is absorbed.

[John Florida]

So if we bagged in mylar bags and sealed in pails but did not vacuum seal how long will it last?  If I toss in some oxygen absorbers how much furhter could I extend the shelf life?

 Years! Michelleo posted that it would last 10 to 20 years.

I can work with that!

 Hell yes!!Now where to get 10 year supply if you don't live in a producing state without getting raped.

If you find out let me know, as it is I'm walking kind of funny, damn I hate that!

 I would check with local farm co-ops or feed stores in the area.I'm not having much luck  so far on line.As far north as you are there has to be a supplier closer than you think.

[Libertas]

So if we bagged in mylar bags and sealed in pails but did not vacuum seal how long will it last?  If I toss in some oxygen absorbers how much furhter could I extend the shelf life?

 Years! Michelleo posted that it would last 10 to 20 years.

I can work with that!

 Hell yes!!Now where to get 10 year supply if you don't live in a producing state without getting raped.

If you find out let me know, as it is I'm walking kind of funny, damn I hate that!

 I would check with local farm co-ops or feed stores in the area.I'm not having much luck  so far on line.As far north as you are there has to be a supplier closer than you think.

I'll get my food guru to look into it, let you know what I find out.