Testing eggs for freshness
Many recipes are dependant on the freshness of eggs (e.g. poached eggs must be as fresh as possible and older hard boiled eggs are easier to peel), but if they aren't date stamped how can you tell? The trick is to use the air pocket that forms in the fat end of the egg as moisture evaporates through the porous shell over time. To "age" an egg simply submerge it in a jug of cold water:
If it lies completely flat on the bottom there is almost no air in the shell and it is completely fresh.
If it points upwards, it is likely to be up to a week old - still OK to use but will need to be eaten soon.
If it floats the egg is stale and should not be eaten.