Simply fill a bowl with cold tap water and place your eggs in it. If they sink to the bottom and lay flat on one side, they are fresh and good to eat. A bad egg will float because of the large air cell that forms at its base. Any floating eggs should be thrown out.
Float test
If it sinks or stays at the bottom, it is still fresh. An older egg will either stand on its end or float. The float test works because air builds up inside the egg as it ages, increasing its buoyancy.
The water test for egg freshness
First, fill a bowl or glass with about four inches of cold water and gently place your egg(s) inside. Very fresh eggs will sink to the bottom and lay on their sides. If an egg stays at the bottom but stands on its small end, it's still acceptable to eat; just not quite as fresh.
You can eat eggs past their expiration date. Just be sure to keep your eggs egg-cellent by storing them correctly. If you don't know if an egg is good or not, you can try the float test or give it a whiff. If it doesn't pass the test, throw it away.
If they sink to the bottom and lay flat on one side, they are fresh and good to eat. A bad egg will float because of the large air cell that forms at its base. Any floating eggs should be thrown out.
Carefully lower your eggs into fresh cold water using a spoon (you can do this in the pan if you're about to boil them). If the eggs stay at the bottom they're fresh; if the eggs float, however, they're stale and best avoided.
Eggs may be refrigerated three to five weeks from the day they are placed in the refrigerator. The "Sell-By" date will usually expire during that length of time, but the eggs will be perfectly safe to use. Always purchase eggs before the "Sell-By" or EXP (expiration) date on the carton.
As long are they are kept refrigerated at 45 °F or lower, fresh shell eggs are safe to be consumed four to five weeks beyond the carton's Julian date (the date eggs were packed).
Old eggs should always be disposed of responsibly to avoid contamination and food-borne illnesses. You can choose to compost, feed them to animals, recycle them at local centers, or throw them in the trash. Eggs with foul odors or discoloration may be spoiled and should not be eaten.
Place your eggs in the water. If your eggs sink to the bottom and lie flat on their sides, they are very fresh. If your eggs stand on one end at the bottom, they are a few weeks old, but still fine to eat. If your eggs float to the surface, they are no longer fresh.
The older an egg gets the more gas builds up inside it. More gas = more floating!
Perhaps the most common problem with hard-boiled eggs is overcooking. That's what happens when the yolks are pale yellow with that familiar green band around the outside. There is frequently the odor of sulfur. This is due to a reaction between traces of iron in the yolk and sulfur in the white.
Osmosis will occur; that is, the water will migrate from the side of the membrane where water molecules are abundant (i.e. outside the egg) to the side where water molecules are less abundant (inside the egg). After 24 hours, the egg will be plump again!
To avoid getting a green yolk, cook your eggs just long enough to reach the desired doneness—no more. And quickly plunge the cooked eggs into cold water to stop the cooking process and minimize the iron-sulfur reaction. Some people also say that the cold-water plunge makes eggs easier to peel.
The reason some recipes call for water, milk, cream, or half-and-half is mainly as extra insurance to prevent a rubbery texture. A small amount of liquid dilutes them, which stops the proteins from bonding too fast and tightly together.
As a result, if you choose to use eggs after the best before date has past, make sure that they look and smell normal (odourless), and use in baking or other dishes where they will be thoroughly cooked. Throw away any eggs that smell rotten or bad upon cracking the shell.
According to the USDA: A "best if used by/before" date lets you know how long the eggs will be at their best taste and highest quality. You can definitely still eat eggs once this date has passed (as long as they aren't spoiled). A "sell-by" date lets the grocery store know how long it's okay to still sell the eggs.
Eggs are a potent source of calcium, phosphorus, potassium, and nitrogen that are required by plants for healthy and robust growth. When you bury a whole egg in a planting hole, it takes a while to decompose and acts as a slow-release fertilizer that gets leached into the soil, thus benefitting the plant growth.
You may have heard of a method called the float test or the water test, which involves placing an egg in a bowl of water and seeing if it sinks (meaning it's good to use) or floats (no good). The theory is that, as an egg ages, the air pocket inside it grows larger, buoying an old egg to the surface.
An unwashed egg will last for 6 months or more in the refrigerator. If the fresh eggs have been washed, then the shelf life will be similar to a store bought egg - about 4-5 months.
Here's What Fresh Eggs Daily Tells Us:
And farmers have up to 30 days to go from when the egg is laid to the carton. That means those supermarket eggs can be two months old by the time you buy them.