
The Hen
With its ancestors being native Jungle Fowl of South East Asia, hens have been kept in
Grade "A" Eggs
Under EU rules only Grade A eggs are allowed for retail sale. This means that they must have
In addition Grade A eggs must not have been washed or stored below 5 oC.
Egg Sizes
Eggs are sized and packed in 10 gram bands:
The average weight of an egg is about 63g and over 90% of eggs are Large or Medium with only 5% each of Very Large or Small
Egg Diagram

By weight an egg is 11% shell
58% white and 31% yolk
Freshness
As an egg ages it gets lighter through evaporation and the air space grows. Hence the old water test for freshness - a fresh egg sinks and an old egg floats. When broken a fresh egg shows a clear distinction between the thick inner white and the thin outer white. With age this becomes less distinct and the egg spreads more on a flat surface.
Typically eggs reach the shops within 2-3 days of being laid.
Under EU rules they are given a maximum best before date of 28 days but the British Lion Code sets a shorter life.
Storage
Eggs are much better (and safer) if kept cool, either in the fridge or a cool larder. They should be stored vertically with the blunt end upwards - this prevents the air cell trying to change ends and push the yolk off centre. And finally, keep well away from anything with a strong smell.