The mass production of eggs is essential if the consumer demand is to be met.  The egg industry is a highly developed and technical industry.  To achieve success, the producer must be something of a scientist, a nutritionist, an engineer and a businessman.

A modern poultry farm, eggs are gathered daily.  they are then graded according to quality of the eggs is determined by means of the candling method without having to break the shell.  Each egg rotates under a harsh light.  The quality of the egg yolk, the white and the air space is monitored and eggs which don't conform to requirements are thrown out.  Blood and meat specks are abnormalities which are shown up by the light.  Normally these eggs don't reach the consumer, but should eggs with small specks on the yolk and white slip through, it is important to remember that these are harmless and have no effect on the use of the eggs.

Tfreshnesshe quality of an egg is determined by the size of the air space.  As the eggs is determined by the size of the air space.  As the egg deteriorates, the air space expands.  Thus the freshness of an egg can be tested by placing it in a bowl of salt water.  The fresh egg will lie on it's side on the bottom, an egg one week old will lie on the bottom at an angle and eggs of two to three weeks will stand upright.

When breaking open a fresh egg, the yolk will form a nice firm dome while the white will lie stiff and firm around the yolk.  With less fresh eggs the yolk will appear flat and the white watery.  When eggs are older than three weeks, the membrane around the yolk tears and the yolk spreads.  The white is completely watery.

The sizes in which eggs are marketed are as follows:

EXTRA LARGE - eggs with a mass of 61g to 66g (red)
LARGE - eggs with a mass of 51g to 61g (blue)
MEDIUM - eggs with a mass of 43g to 51g (green)
SMALL - eggs with a mass of 35g to 43g (black)

Although JUMBO eggs (purple) are found in the trade, this mass group is not officially defined.  These are usually eggs weighing more than 66g.

These grade standards are set and enforced by the Directorate of Agricultural Product Standards.  Inspectors of Directorate follow up all complaints with regard to egg mass.