Remember Dug's joke from the movie Up?
"Hey, I know a joke! A squirrel walks up to a tree and says, 'I forgot to store acorns for the winter and now I am dead.' Ha! It is funny because the squirrel gets dead."
Well, I don't get it. It makes me laugh, though, because the dog is telling a joke. That's funny. Sort of like my daughter's muffin joke that goes like this:
"Two muffins were baking in the oven. One muffin said to the other, 'Man, it's hot in here.' The other muffin said, 'Aaaagh! A talking muffin!'"
Then there's that joke about sour cream going bad. That's another one I don't get. Everything goes bad, even under ideal storage conditions. Everything peaks, then begins to decline. Even blue cheese gets a little more blue. We don't consume much cheese or sour cream at home, and I've made peace with waste. I don't know that we're going to get sick from extra-blue cheese, but I replace it knowing that at the very least, the cheese is no longer good. The mold that gives it its flavor to begin with has overrun the cheese.
With a few exceptions (leftovers and orange juice among them) I'm not a keen observer of dates on the foods in our fridge. This horrifies everyone else under my roof. But I'm the main shopper and cook and feel confident in my assessment of freshness. But it'd be nice if there was a firm date on things. A "Don't Even Consider Eating Past" date. But that doesn't exist.
I poked around the USDA for a bit and found no hard answers. I think it's because the rate of deterioration is very much dependent on storage conditions. The "Sell-By," "Use By," and "Best if Used By (or Before)" are mostly recommendations. In fact the dates on packaged foods we call expiration dates are not safety dates, they are the manufacturer's estimation of freshness. Only infant formula and some baby food have hard expirations and cannot be sold once those dates have passed.
I wish I had something concrete, other than the old smell-it or pour-it-in-your-coffee-and-see-if-it-curdles test. But I think I'll have to continue to convince my family that milk past the date on the container is fine until I say it's not.
Here's some guidelines from the USDA:
Always purchase eggs before the "Sell-By" or "EXP" date on the carton. After the eggs reach home, refrigerate the eggs in their original carton and place them in the coldest part of the refrigerator, not in the door. For best quality, use eggs within 3 to 5 weeks of the date you purchase them. The "sell-by" date will usually expire during that length of time, but the eggs are perfectly safe to use.
My own rules:
1. Leftovers and deli meats must be eaten within 72 hours of the time you first put them in your fridge.
2. Buttermilk is usually fine for a month past the date.
3. Cream cheese and sour cream should tossed one week after opening the package, regardless of the date on the package.
3. Dispose of anything that smells bad, meat included. Get used to smelling things. If you plan to eat it, you should be willing to smell it.
More time to kill? Read Food Expiration Dates: What Do They Really Mean? From Swedish Medical Center in Seattle.