why do raw eggs float in water

Firstly, fill a fairly deep bowl with water. The level of the water should be approximately twice the height of the egg. Then, carefully lower the egg into the bowl. There are three things that could happen. In the first instance, a very fresh egg will immediately sink to the bottom and lie flat on its side. This is because the air cell within the egg is very small.

The egg should also feel quite heavy. A slightly older egg of about one week old will still lie on the bottom of the bowl but at a slight angle. It will bob up and down rather than lie still. Gradually, as the days pass, the egg will start to lose its freshness and more air enters the egg, at which point it will begin to float and stand upright.

The smaller end will lie on the bottom of the bowl, whilst the broader end will point towards the surface. However, the egg will still be good enough to consume. Here, the egg is about three weeks old. Finally, if the egg fully floats in the water and does not touch the bottom of the bowl at all, it should be discarded, as it will most likely be bad.

A bad egg will also feel extremely light in weight and give off a pungent smell.
Throw out any eggs that have been refrigerated and then sat out at room temperature for two hours or more. Once an egg has cooled in your refrigerator, it is important to keep it at the same temperature. A cool egg in a warmer environment begins to sweat, which can encourage bacteria to grow on the outside of the egg.

Because the egg shell is porous, it is sometimes possible for the bacteria on the shell to pass into through and contaminate the egg. To prevent temperature fluctuations, store your eggs in the coldest part of your refrigerator, not on the door. The temperature is more likely to fluctuate on the door when it is opening and closing, which may cause your eggs to sweat.

If you receive your eggs unwashed and at room temperature, they do not need to be refrigerated. Many countries, including most European countries, keep their eggs at room temperature. This is safe because the hens have been inoculated against Salmonella prior to laying their eggs.