Shelf Lives
 

I realized yesterday that I didn’t have the cornstarch a recipe called for. I texted my father in law and he brought over a container. The expiration date in a year out. He didn’t buy it and his wife has been deceased for almost 3 years. She was sick and not cooking for the year prior to that. So, this stuff must be good for at least 4-5 years. What products have a longer shelf life than that? I thought 4 years or more was pretty extreme.

It's kind of a tricky question, because it depends on what you mean by shelf life, and under what conditions. If you're going simply by the "best by" date, 4 years is a long time. If stored in completely air-tight, moisture-free places, a lot of dried pasta and grains can last well over 10 years though. Things like liquor, salt, and vinegar can last pretty much forever. Then you have a whole category of dried and freeze-dried foods. I still have some leftover freeze-dried meal packs from my hiking days from Mountain House. I believe they guarantee 30 years if they remain sealed.

For normal foods, stored in a typical pantry, I'd agree 4 years is pretty good :).

I came across a magazine article today that spells out a few items. Low acid canned foods can be safe to eat indefinitely as long as the cans aren’t rusty, swollen or dented. Acidic foods might only be good for 18 months to two years. White sugar has no expiration date. White rice can last 25 to 30 years. Vanilla extract and salt can last virtually forever. I wonder if manufacturers still put “best by” dates on them to promote buying replacements.

I suspect it's driven by the manufacturers' liability insurance carriers.

Our USAR team at work apparently stocks enough emergency rations to feed the whole company for a couple days. It's in the form of foil wrapped cookie things that are kind of like shortbreads. Several years ago someone who is on the team offered me some that were 5 years post expiration. They have a nominal 5 year shelf life, so 10 years old at that point, figuring (correctly) that I wouldn't have a problem trying them, and if they weren't stale or nasty would snack on them. They were fine. So much so that I ordered some for my own earthquake kit.

Lots of dried herbs and spices are usable well past their expiration dates. Mostly they just lose flavor over time.

A colleague visits a research station in the arctic that has 40+ year old cans of Spam that everybody assumes are fine, at least to the extent that Spam is ever fine.

Flour can last a long time (years) if you keep it dry.

Honey will crystallize, but last millennia. All you have to do is gently heat it in a water bath and it will turn back to honey.

My mom had a single jar of mayonnaise in the fridge my whole life. The same jar. None of us use mayo, and we were all afraid of it, so it just lurked there. We always assumed it was bad, but except for one of my sisters we all assume that all mayo is bad.

Cornstarch should good indefinitely if you keep it dry and free of bugs.