My thoughts, when you do the next grocery shopping, replace them. Then have them for dinner soon. That will let you know real fast how well your storage method is working over 18 months or so. Look at them carefully. Mold, fungus, bad smells, unusual texture and such, trash them. Bugs and such, cook well. Thats protein in dinner.
As to them for dinner, I would eat/use/cook them in a heartbeat. FDA basically requires everything to have a one year maximum expiration on them. Recently there was reports that that was being extended and recommended that people use things beyond that date.
My methods are basically, canned stuff is good as long as the can is still sealed and not bulging. Taste and such is less than optimal in the stuff but otherwise, no problem. Tomato soup may not be real good in 10 years but it will be edible. Other home sealed stuff is vacuum sealed in bags, about 1 pound of beans or rice or such each, with small O2 absorber. From there to buckets.
I store mine in 5 gallon food grade buckets. Easily obtainable at most local restaurants. That bucket is lined by a polymer bag large enough to take everything and seal up. Basically, bucket gets bag, bag gets towel or such in bottom, covering chunk of dry ice. Content gets put in and bag is sealed up all but last couple inches. That gets clothes hanger clips holding it closed so dry ice melts and fills bag, pushing atmosphere out. Bag blows up, gets squeezed down and clipped again. Blows up, squeezed down, clipped. After it is about all blown out from all dry ice melting, a couple larger O2 absorbers go in, along with a one pound cardboard container of salt. That has a half dozen small holes punched into it to absorb an leftover or frozen moisture. Sealed down to 1/4 inch which gets vacuum pump to suck out everything it can, then bag sealed, dry ice outside bag in bucket and lid put on. Touch of leak to let pressure out of bucket outside so CO2 pushes out atmosphere and when that stops it gets sealed. Just before sealing gets couple more O2 absorbers
Each bucket gets foodstuffs, pair of socks, underwear and such, plastic forks, few strike anywhere matches and such. Some buckets are also set up as grab/go supplies, others are basically food/eating stuff. Each bucket planned before packing it starts.
Each bucket gets a contents list in envelope on outside and numbered for entry into each copy of master supply book.
Yes I imagine my methods are probably triple what is really necessary, but I want it be there if/when I have to rely on it.
Also look into the Mormon Church food storage centers. You can buy #10 cans or big bags of stuff there for most excellent prices. Look all over that Provident Living website. You will learn more than you think you ever could learn. See link below.
Nemo
http://providentliving.org/self-reliance/food-storage/home-storage-center-locations-map?lang=eng
