Matt Springer has been giving presentations around San Francisco about home earthquake preparedness since 2008 (for more information about the presentation, go to his earthquake preparedness website). For those who cannot attend in person, a streaming version of the presentation is available online. This Quaketips blog is devoted to posts ranging from technical "how-to" articles to more philosophical "should-you" topics. New articles will be posted at most about once a month, so people who subscribe won't be subjected to lots of e-mail.

The suggestions contained in this website and in Matt Springer's presentations will substantially reduce the chances of an earthquake causing damage or injury, but cannot guarantee that problems will not still occur due to factors including but not limited to extreme seismic conditions, unexpected structural problems, bracing material flaws, or inadequate installation. This material is based on personal experience, research, and discussion with safety experts; Matt Springer does not have an official emergency management background other than standard community volunteer training. The information contained herein does not necessarily reflect the views of UCSF or the San Francisco Public Library.

Wednesday, January 13, 2021

MRE shelf life follow-up follow-up: Ever wonder what a 21-year-old MRE tastes like?

“Previously, on Quaketips”

2013:  MRE shelf-life follow-up: Ever wonder what a 14-year-old MRE tastes like?

“Several days ago, I ate an MRE with an 'expiration date' of 2005, and lived to tell about it.”

“...May of 2011, I wrote an article about MREs in which I reported that while MREs have long had charts from suppliers showing shelf lives as long as 10 years depending on ambient room storage temperature, the official estimated shelf lives had recently been made considerably shorter.  However, I also reported that this was based not on “going bad” but instead on subjective taster opinions about when the meals were no longer at their best flavor and texture, and that there was every reason to think that they would be edible and not harmful for years to come.”

“I purchased a new batch (this will be 2013-2020), planning to keep the remaining 2005-2012 MREs as backup, and found again that a new meal that I tried was better than the expired 2005-2012 MRE, but the expired one was not bad.  So naturally, I had to find out what had happened to the ones with 2005 expiration that I had been keeping as a back-up.”

“...the 2005 ‘expired’ meal, which was packaged in 1999, was about as good in 2013 as it probably would have been in 2005.”

“However, I think I’ll stash one or two of them away to test in 2020, out of morbid curiosity, and I’ll report back...I guess that means I’m committing to this blog for at least 7 more years!”


And now, the conclusion:

2020 was the target year that I set forth in my earlier article, 7 years before that.  Not that there’s anything magic about 7 years; it was the approximate stated life of the MREs stored at the temperature of the closet in which they had been stored for 7 years before that.  My current closet is colder, so that would presumably increase the time window for this somewhat arbitrary guideline, so it’s ok to do it in 2021.

OK, actually, the reason I waited until 2021 to try my 21-year-old MRE was because it simply seemed like a bad idea to try eating theoretically expired food in the year 2020…

So on January 1st, 2021, I dug out this very old MRE that has been sitting in my emergency supplies all these years.  With anticipation, I opened the outer package.  No goblins or hairy things emerged.  More importantly, there was no bad aroma, and no ballooning packages.  Interestingly though, there was a slight smell of mint when I opened the outer package, which turns out to have been from the pair of green (I presume that was the original color) spearmint chewing gum squares that were wrapped in cellophane inside the package of napkins and spoon, inside another thick sealed plastic bag.  I don’t recall that happening in the identical menu MRE that I tried in 2013.

So that means that some molecules can very slowly pass through multiple layers of plastic if given a couple of decades.  Keep that in mind (foreshadowing!)

I remembered that the jam does not age well, so I opened the jam for the heck of it and sure enough, very dark and gloppy.

The chocolate covered oatmeal cookie was PERFECT.  I mean it was really delicious, no hint of anything wrong, it was EXACTLY like its siblings of various younger ages.  I ate the whole thing as a New Year’s Day dessert.  Good stuff.

The crackers were in reasonable shape but there was just the slightest aroma of old cooking oil or old nuts (oxidized oils).  I took a bite and it was fine but it had the slightest old taste to go with the old smell, so I opted to not continue.

The real discovery was the beef stew entrĂ©e itself.  I already knew from last time to expect it to not look appetizing until it was heated up, and this indeed was again the case.  However, unlike 2013, this had a mild old oil smell like the crackers.  I would not say rancid; it was not terrible but since the mildly unpleasant aroma was there, I decided to not eat any.  I don’t think it would have made me sick but something was clearly off that wasn’t off 7 years before.

This mild odor suggests to me that the process that ultimately makes old MREs undesirable is slow lipid oxidation of the natural fats and/or added oils.  Since nothing was growing in the MREs after 14 years (for that matter, after even just a few months), I don’t feel that one would get food poisoning.  However, it sounds like enough oxygen was able to get into the beef stew and the cracker packages, despite their individual vacuum-packaging and the outer bag, that the oils were oxidizing over 21 years to the point that the food was affected.  So my recommendation from this experience would be that while 2 lifetimes are probably fine, don't push it to 3 lifetimes.

However, here’s an important point to consider.  These late 20th Century MREs have partially hydrogenated oils in the ingredients lists of most of their components, and one of the reasons that partially hydrogenated oils used to be popular in the food industry was that they were very stable and could bestow a long shelf life on baked goods and Oreos and Pop-Tarts, etc.  They were phased out of the food supply (at least in the US) many years ago though, because of our modern understanding of their harmful cardiovascular effects.  I did notice some partially hydrogenated oils included in the "sub-ingredients" of something called grill seasoning in some of the more modern MREs, but it's presumably at lower levels than before.  I wonder if as a result, this lipid oxidation will occur faster in modern MREs and their shelf-lives will thus be shorter than the MREs made in the late 1990s.  

As a result, what any of us learn about currently old MREs may not be applicable to modern MREs when they reach a comparable old age. 

Now a limitation, as we would say when describing a scientific experiment, is that this was “an n of 1;” that is, it was just one MRE and perhaps it’s the exception rather than the rule.  However, in 2013, I tried several of the 1999 MREs including one with identical ingredients to this one, and all of them were fine; and in this MRE, more than one component had the old oil smell.  That makes me pretty confident that what I’ve observed is real (at least for Mil-Spec brand MREs).

So my conclusion from this very long experiment with pre-Y2K rations is to keep "expired" MREs around as a back-up set for one extra shelf-life.  And with that, I think I'll stop looking for old food to eat--although--wait, didn't the ancient Egyptians leave food in the crypts with their deceased Pharaohs?  Hmm...


3 comments:

  1. Amazing! I've been waiting years for this and it was everything I'd hoped for.

    ReplyDelete
    Replies
    1. We aim to please! Now celebrate with a fine aged wine... preferably not taken from a French MRE...

      Delete
  2. great follow-up. thanks for taking the time to finish this "MRE Expiration" report. (including the effort to keep track of 'old' mre's after the move. cheers

    ReplyDelete

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