Two new ones.
First was grated cheese. I pulled two cans, one from 2014 and the other from 2015:
Observations: Both had the foil seals. The 2015 was bulged up, the 2014 was still vacuum sealed and hissed when I broke the seal. The 2014 smelled and tasted just like new despite its darker coloring. The 2015 smelled off, so I threw it out after taking this photo. I've been eating the 2014 and it has been fine, a little sharper taste than fresh which I think is just the normal cheese aging effect. I'm unsure why the color darkens, all I know is it's edible and tastes good. Every can I have darkens with storage time from light yellow to almost an orange.
Second victim was the one I really was interested in. Ground Coffee. Everything I read, even on prepper sites, talks about how grinding the bean lowers the storage life and it goes bad in a year, you need to refrigerate it, don't freeze and unfreeze, etc, etc. This shit drives me crazy because IT'S JUST TALK. There's not one goddamn actual person out there I could find storing shit and reporting. 30ish sources all saying one year, maybe two and not to store it ground. No facts, just parroting garbage and believing it. So here we go with *GASP* actual real life research.
These were 2012 #10 cans of your basic generic coffee. I bought these on sale from BigY in CT at $5 per can during a sale to purge their inventory. Yeah I said $5 per can. You can see the best by data was 4/2014. Upon opening the foil was still vacuum sealed. Coffee grounds were still separated, no clumping. Smelled like a new can. Perked some up and the taste was as expected for low shelf coffee. It passes with coffee taste and no real body to the flavor, but you bet your ass I would drink this everyday if I had to.
This is regular ground coffee, stored in the original container, on a basement shelf, with no humidity control and temp ranging from 55-70 degrees based on seasonal changes. It's also been moved twice over that time frame, so three different basement environments. It's perfectly fine. I am going to continue buying ground coffee like this and storing it.
I have 10-15 of these from the same lot. I will open one a year to report. Based on the quality at 4 years, my guess is it will go at least 10 with no appreciable difference. I bet the can is the limiting factor and will start to rust or lose seal before the grounds go bad.
This is why we need more people contributing to this thread. I'm sure there's all sorts of items out there we could all be storing at an extremely lost cost that last far longer than anyone realizes.