Expiration Dates
Jane Brody in the NYTimes last month had an article about the expiration date labelling on packaged food. The article has gone to the NYT Pay Archive Heaven, but is apparently syndicated to other publications.
Anyway, the gist of the various food dates is:
- Packed on: when food is put into the packaging, and is only marginally useful, as you don’t know how long the fruit (for example) was sitting in the factory before being put in the box. For frozen, use in a few months. For canned, in a year.
- Sell by: the store pulls the food from its shelves after this date. Food can be safely consumed for a bit after the sell-by date, e..g, milk for about a week after the sell-by. (I think NY City actually has a milk sell-by that’s a few days earlier than elsewhere in the state, under some notion that refrigeration may not be as consistent because of the many deliveries to small stores. Whether this is an issue or not, I don’t know. In any case, I tend to use milk to make yogurt, so the sell-by is less of an issue.)
- Use by: the consumer should use up the food by this date if he’s concerned about top quality. The food should be safe to eat for a few days past the use-by date, though. Cereal, for example, has the best-if-used-by date, meaning that the cereal has a higher chance of being stale at this point.
- Expiration date: food with this marking shouldn’t be consumed after this date. This is probably the clearest labelling in terms of whether the food is still good or not. Brody notes that eggs are probably safe for a month after their expiry date (assuming proper storage) because their expiry dates have to do with a Federal regulation that states that the expiry date should be 30 days past their packing date.
Actually, regarding eggs, here’s a trick for determining useability that I remember from Cooking for Dummies: put the eggs in water. If the eggs float, toss them in the garbage. If they sink, then they’re good. Intermediate buoyancy becomes a judgement call.
Of course, one shouldn’t give up common sense regarding bulging canned goods, stinky milk, fruit with unexpected and unfortunate things growing on the surface, etc.