# Canned food storage vs Temp (longevity)

Hi all.

We’ve all heard that old adage about keeping food stored in a cool dry place.

And I got to wondering about canned food. Now, under normal conditions (like in your house or basement), even a year or two doesn’t seem too bad (probably somewhat dependent on what it is though).

Now, lets say I live in the south and decide to store all my canned food in the shed out back. Most of the time it will be hotter than my house. And for six months of the year its gonna be WAY hotter than my house (40 degrees wouldn’t be a stretch for peak months).

How much faster is that canned food going to “go bad”. Does one year in the shed equal 10 in the house pantry?

From here:

Thanks for that info Donkey.

During yet another restless night trying to sleep I remembered something from chemistry class (which may or may not be true depending on my memory).

I seem to recall something about chemical reaction rates doubling for every 7 degrees higher in temp?

If something like that was true and it was also a guide to food just degrading, then a 21 degree higher temp would mean an 8 times faster degradation. And 28 would be 16 times faster!

If that or something like that is the case I can see how high temps are a bad thing for any length of time.

Apparently something is my favorite word of the day

Hmmm…Canned food are sterilized, no? So, couldn’t you keep them for 10-20 years, rather than 1-2 years?

Assuming that the cans have been stored properly, yes. The “expiration date” on cans is really more of a vague guideline than anything else.

I could believe that this holds approximately for a particular reaction, over some range of temperatures. I doubt it would be a basic law, though. Different reactions could have different doubling constants, or not really follow that law at all. The point about chemical reaction rates increasing with increasing temperature should generally hold.

That’s exactly right.

A simple reaction, whose kinetics are limited by thermal activation over a single barrier, follows the Arrhenius law, a consequence of statistical mechanics. The rate depends exponentially on the reciprocal of the absolute temperature. The steepness of the exponential is determined by the height of the energy barrier of the rate limiting step. Over a restricted temperature range, well above absolute zero, the rate can be approximated as an exponential in the temperature difference from some reference temperature.