My Experience with Almonds & Walnuts LTS

I do wish someone on this board had access to a lab for rancidity testing.

Nut oils are fragile, but polyunsaturated oils are well known to last longer in whole nuts/grains than if ground, sliced, or diced. My experience is that nuts do considerably better stored with oxygen absorbers than with just vacuum canning, but I've never seen anything on nuts in their shells canned that way. It would be nice to see some solid lab numbers on that, since they do keep better unshelled than shelled when raw (25% to 50% longer on average). It would also be interesting to see how getting them out of contact with all oxygen after shelling works versus intact nuts in their shell in a zero-oxygen environment. All the available data is based on either vacuum-sealed in plastic whole nuts or nitrogen-flushed shelled nuts in cans/jars.

Ideal storage for most nuts is supposed to be 0 to 10 C at 50% to 70% humidity, so I expect the fact the OP had his refrigerated for half the storage time and in a cool house the rest had a lot to do with his satisfaction when he opened the cans. He's going to get noticeably less shelf life with them stuck under the house where it gets to 80 degrees in the summer.

My recommendation would be to package with O2 absorbers and freeze. If using shelled nuts to save space, also apply some rosemary-tocopherol-ascorbic acid antioxidant before packaging. Almonds will last noticeably better than walnuts, but even walnuts and pecans should have at least a 2- to 3-year shelf life frozen in zero oxygen, and unshelled almonds should still be good for a year or two after defrosting if you stick to a 2-year rotation in the freezer.

While I agree with Zeke that the ideal solution is to plant a bunch of nut trees on your property, I am one of many for whom that advice isn't of much use. So it would be really nice to see some hard numbers on how the oils in various nuts and oil seeds fare in different storage conditions in a zero-oxygen environment.

ETA: Blue Diamond gives its raw almonds in the shell stored in ambient conditions in plastic bags a 36-month shelf life, so the OP may be quite right that those were fine after 5 years stored in cans in a zero-oxygen atmosphere. I would doubt his wife's nose if she thinks the walnuts are equally good, but she may be quite right about the almonds.
http://www.bdingredients.com/food-safety/
Unfortunately, their only canned products have been sliced/diced/chopped and/or blanched or roasted, all of which things greatly decrease shelf life, so no numbers for unshelled almonds packaged with oxygen absorbers.

ETA:*Rainy Day/Walton gives its shelled pasteurized raw almonds in #2.5 cans up to a 3-year shelf life stored at 60 degrees or less, but I have no information on what they base that on. Blue Diamond gives its whole natural pasteurized shelled almonds in nitrogen-flushed cans a 2-year shelf life for normal pantry storage (which they have to assume is going to be more like 70 degrees or above) on the linked chart, but the cans I have here have a best-by date 3 years post manufacture. I count my shelled almonds packaged with oxygen absorbers and antioxidant and frozen as good for 3 years in the freezer and another year on the shelf or 2 years in the freezer and another 2 on the shelf although I have no Rancimat numbers to prove it. In the shell, I would think that you ought to get up to 3 years in the freezer and another 2 on the shelf. (I don't have enough freezer space to freeze in-shell nuts, though.) Walnuts or pecans would have shorter storage lives. Planters dates its walnuts in nitrogen-flushed canisters for 1 year. I can't remember what Diamond gives its similarly-package walnuts with added BHT, but it may be as much as 18 months. Of note, there is research showing that most of the rancidity in walnuts is oxidative, so storing with an oxygen absorber should give much better results than vacuum packaging and somewhat better results than nitrogen flush as well.
http://pubs.acs.org/doi/abs/10.1021/jf60030a006?journalCode=jafcau
If packaged with an oxygen absorber and natural antioxidant, you should be able to store your walnuts and pecans frozen for a couple of years or frozen for a year plus a 6-month to 1-year pantry shelf life depending on temps. I would devote more of your freezer space to longer-lived nuts like almonds, though. (Note, sunflower seeds have a 1-year storage life in ambient conditions, so are intermediate between almonds and pecans or walnuts.) I really wish some of the oxygen absorber manufacturers would sponsor some rancidity studies on various varieties of nuts packaged with them rather than nitrogen flush. Given that most of the rancidity in nut oils is oxidative, there should be a real difference between storage in 2% to 3% oxygen and storage in less than 0.01% oxygen.

I agree that nuts are not long-term storage candidates other than growing them on trees, but there are ways to get them into mid-term storage on a shortish rotation. As with oils, the way to do that is to use a freezer up until the lights go out. With oils, you can also add some antioxidants to cold-pressed oils and nitrogen-flush the jars or cans for max shelf life. With nuts, you add some antioxidants and package in mylar or jars with O2 absorbers. You should be able to store a couple of years of nuts used on a regular rotation or your current harvest plus a year's backup supply off your trees. (Since nut trees don't necessarily give you a nice harvest every year, especially if you don't have an orchard-full of the things, getting a couple-of-year storage life is of interest to even most of those who have trees.)

jgonz123 said:

Thanks again NYMin for the detailed reply. I am a little surprised they even posted the 3 years category. The pessimist in me ponders if they ever do testing whether they would release results that raw unshelled almonds canned with OA @ ambient temps might last medium term, such as 7 years.

Click to expand...

The problem there is that the nut companies have ways they have always sold their product and don't see any compelling reason to retool their factories or change their packaging.

Unshelled nuts are sold bagged or in cartons, and that 3-year shelf life is of interest to the wholesalers who buy them that way. Shelled nuts are sold either bagged or jarred or in nitrogen-flushed cans/canisters for longer shelf life. Naturally, they only test shelf life for the products they sell in the packaging they use. Unless Diamond or another manufacturer sees a reason for switching to canning with oxygen absorbers that justifies retooling their factories, we aren't going to see shelf life for canned with oxygen absorbers. Quite the contrary--what I have seen in recent years in the food industry is a big shift to plastic packaging for foods even though the shelf life is less. Storage life no longer seems to be of much interest to purchasers, who rarely keep much in a pantry any more, and therefore is no longer much of a priority for food packagers.

Like you, I think where oxidative rancidity is the major issue, shelf life with oxygen absorbers is going to be noticeably better than shelf life with just nitrogen flushing. The big question is how much better. Which is why I really wish someone interested in these food storage questions had access to a laboratory for rancidity testing and the knowledge about how to test high-oil foods like nuts versus extracted oils. I don't think 7 years is likely to be achievable for nuts, but it may turn out you can get 3, similar to olive oil, for some natural nut varieties stored in cans with oxygen absorbers, with more requiring a freezer (as with olive oil).

The problem is that I just don't know, so I save my freezer space for nuts and oils to be sure a 2-year supply remains good for a decent rotation. The problem with going for a longer storage life absent testing is that one of the main reasons for storing nuts is their essential fatty acid content, which is exactly what you lose when they start to go rancid.

To add some fuel to the debate fire here, pine nuts are generally quoted as having a shelf life of only a few months, but if you buy the Italian pignolias canned in little glass jars, they are dated with a best-by 3 years from manufacture, and do seem to keep that long stored in the dark in a pantry cabinet. So packaging obviously has a huge impact on shelf life there. The problem is that there is very little to be found in the way of research on rancidity of nuts in modern food-storage packaging with oxygen absorbers, and where there is rancidity research on other products, it turns out that the answer is frequently not what was expected, so you can't go on nothing but assumptions.

OTOH, we do know that shelf life for other foods is vastly different when vacuum packed in plastic or nitrogen flushed in cans, and that the difference in shelf life and quality when packed with oxygen absorbers rather than nitrogen flushed is sufficient to have caused all the major reputable food storage companies to switch to oxygen absorbers. The info on nuts just not storing is still based on nuts vacuum packed or nitrogen flushed. I don't think anyone has gone back and retested for oxygen absorbers, and I would dearly like to see some solid numbers on that. I think they would likely move nuts into good for medium-term storage. Since they are healthy sources of protein and essential fatty acids plus a number of vitamins and minerals, I agree they shouldn't just be written off as unsuitable for storage.

jgonz123 said:

My previous post was intended to convey the difficulty for us lay to get specific advice. . . I did learn a lot from this forum, though it did take me quite a long time sifting here and other spots trying to find a best-case solution for storing nuts as long as they can, then knowing approximately what that duration is.

Click to expand...

I'm with you on trying to find some solid numbers on how various nut varieties fare with current best-practices storage. I don't think the cookie-cutter numbers generally handed out on shelf life are the whole story. Not only are there big differences between almonds, pecans, peanuts, walnuts, macadamia nuts, and pine nuts in oil content and pantry storage, but most of the advice on shelf life is based on nuts bought in cellophane bags put on a pantry shelf or tossed into a freezer. Those numbers aren't likely to reflect the true shelf life in a zero-oxygen atmosphere inside an impermeable container.

But then I'm the gal who refused to accept there was no way to store brown rice for more than a year--and found it could keep for 7 with just a little work before storing it.

So oils and oily foods are the hardest things to store, have a shorter shelf life than any other foods under the same storage conditions, and rancid oil is as bad for you as transfats. OTOH, essential fatty acids are essential, are probably the most overlooked and understored dietary item among preppers, and it is worth considerable effort and experimentation to find a way to include nuts and other good sources in your medium-term storage. As with oils, there are going to be real differences in shelf life between different kinds, and packaging is going to make a lot of difference as well

And grow a tree is, indeed, in much the same category of advice as grow and can all your own fruits and veggies or keep your own chickens and a cow and don't worry about storing eggs and butter. Excellent advice for those in a position to follow it, and there is no question being able to produce food versus just storing a year or two of food is the only answer to surving TEOTWAWKI. On the other hand, some of us see a value to having a year or two of stored foods for lesser emergencies, and plant an orchard or buy a cow just isn't helpful for us in our situations. For us "fake" survivalists, a discussion of other options is of interest. It's good to know that canned butter and egg crystals really will keep for 5 to 7 years, versus powdered eggs that are lucky to meet edibility standards for even 1 and butter powder that is loaded with oxycholesterols due to its processing method (also as bad for you as transfats). It's good to know precooked and dehydrated brown rice can be stored for 7 to 10 years in cans with oxygen absorbers. It would be equally good to have solid info on how long various nuts and oil seeds store in cans, jars, and/or mylar with a dose of natural antioxidants and oxygen absorbers.

My only real criticism of your approach is the lack of anything but the nose-and-taste test, which can be misleading. OTOH, if someone who is generally good at detecting rancidity doesn't detect any after 5 years, I think one can assume the nuts were probably good for at least 2 or 3 of those years. The difficulty there is all the people who think coffee is still fresh-tasting after 10 years in a can and nuts in a plastic bag are "just fine" when found after 3 years in the pantry.

IamZeke said:

Defatted nut flour and a stock of palm or coconut oil is how you have survival-useful nuts. That or plant a nut tree.

Click to expand...

I have to disagree with that. Nut flour and palm or coconut oil offers essentially zero EFAs. It's no substitute for nuts, just a way to get some nut flavor back in your life plus fat calories if you need a calorie boost. But it's really in the same category as all other artificial flavors/fake and highly processd foods when it comes to EFA food value--the appearance without the substance. (Plus Emergency Essentials gives their peanut powder only a 3-year shelf life, so you still get peanut butter that is only medium-term storage, not long-term, with that approach. I'd say you would be better off storing whole, raw, unretouched almonds for 3 years and grinding them into almond butter instead.)

The way to have nuts if the world ends is indeed to plant them or know where to forage them somewhere there will be no competing foragers to speak of. Or you could store some seeds for oil crops that will produce in a year instead of 5 if you need to go back to the earth once some of it has been depopulated.

Meanwhile, back where we don't all live in a ranch house, it's useful to know how to get the best shelf life out of nuts and oils that you can, enough to keep a couple of year's supply on hand. While you can survive with nary a nut, around here they are one of my staple foods, so I'd rather not. Same way I feel about brown rice.

As for the fools who insist they've eaten 5-year-old nuts in plastic bags that were "just fine," so they should be fine in cans in the attic for 20, I figure when it comes down to it, Darwin will know his own.

Major Mjolnir said:

? "Serving size ¼ cup of walnuts provides: • 2.5 grams of ALA [alpha-linolenic acid], the plant-based source of omega-3 fatty acid

Click to expand...

Yes, at 2.5 g/oz, walnuts are uniquely high in omega 3 for nuts, around 10 times as much as the next highest--pecans at 0.28 g in an ounce and pine nuts at 0.22 g in an ounce. Then it's pistachios at 0.07 and macadamia nuts at 0.06 g/oz. For oil seeds, chia has 4.9 g/oz, hemp hearts 3.5 g/oz, and camelina seeds 1.9 g/oz, but most other seeds are much lower. Sesame seeds have 0.10 g/oz, pumpkin seeds 0.05 g/oz, and sunflower seeds 0.02 g/oz. A blanket statement nuts are poor sources of omega 3 and seeds are good ones is inaccurate--it depends very much on the specific nut or seed. I am aware of more seeds than nuts that have a high amount, but those seeds are all still among the less commonly eaten here.

What I find most interesting is that walnuts, pecans, and pine nuts are all given similarly short shelf lives in the usual references, yet the Italians manage to package pine nuts to last for 3 years at room temp. So it would seem you can get a reasonable shelf life, one equivalent to the best shelf life for olive oil, for even high-omega-3 nuts if given the right handling and packaging. It's just really hard to get solid information on that. Olive oil has 0.2 g/oz of omega 3, so if you can get a similar shelf life for properly packaged nuts/oil seeds to that you can get for high-quality olive oil in nitrogen-flushed cans, I see no reason not to regard them as equivalently acceptable for mid-term food storage.