What happens to an egg over time? Here’s a way to tell how old your eggs are …

The quality of an egg deteriorates right after it leaves the hen.  A fresh egg white will be cloudy but, as the egg ages, the white becomes more clear and runny.

A fresh yolk has more dissolved molecules than the white, and this osmotic imbalance creates a natural pressure for water in the white to migrate across the yolk membrane.   Each day, five milligrams of water cross from the white to the yolk in each of your refrigerated eggs; the water causes the yolk to swell, thinning it and weakening the membrane.

The egg itself also loses water daily, causing the yolk and white to shrink while the air cell at the wide end of the egg expands.  Because of this moisture loss, there is an easy way to gauge the freshness of your eggs.

Fill a bowl with water and drop your eggs in.  A fresh egg has less air space; therefore it is denser than water and will sink to the bottom.  But, as the egg ages, the loss of water causes the air cell to expand.  The older the egg, the higher the wide end of the shell will rise in a bowl of water.


Check it before you eat!

An egg that actually floats is very old and should be discarded.

NOTE: This is a post I found on somebody’s blog.