Hack busted: The egg float test.
Here’s the thing with the egg float test… It can tell you if an egg is old. But not if an egg is spoiled and unsafe to eat.
First, let’s explain what the egg float test actually does. All eggs contain a pocket of air (called an air cell). In very fresh eggs, that cell is small. But over time, the air cell enlarges enough that the egg will float partially or fully when put in water. So an egg that sinks is pretty fresh while one that floats is a bit older.
But according to the USDA, eggs that float may be perfectly safe to use. The “sell by” dates on the carton may help a bit, but eggs can continue to be safe to eat past these dates as well. So how can you tell if an egg is safe to eat?
The Plate Test
The only way to really tell if an egg is spoiled is to crack it. Put it on a flat plate and let your nose do the detective work. Spoiled eggs give off a unpleasant odor, while safe eggs have barely any scent at all.
Egg Safety Tips
Here are some other tips for safely buying, storing and preparing eggs:
- Only buy eggs from a refrigerated case – if it doesn’t feel cool in the store then buy somewhere else
- Open cartons before you buy them and make sure eggs look clean and their shells are not cracked
- Store inside your fridge (which should be at 40° F or below), not on the door
- Raw eggs should be good in the refrigerator for up to 5 weeks (3 for best quality)
- Hard-boiled eggs can be kept a week after cooking, but dishes with eggs mixed in should be used within 3 to 4 days
- Cook eggs until both the yolk and the white are firm (baked egg dishes should be heated to 160° F using a meat thermometer)
- Reheated egg dishes should be heated to 165° F before serving
For more egg safety tips, download this food facts flyer from the U.S. Food & Drug Administration.