Egg Size, Candling and the Chalaza

Size
Have you ever found an egg in your carton which is smaller than the rest?  Egg sizing is done by the egg’s weight, rather than its overall size. 

Candling

When eggs are being graded they roll over a bright light which makes the egg transparent so the grader can check the inside of the egg for quality. Long ago, candling was done by holding the egg up before a lit candle, which is how this part of the grading process got its name. Today eggs pass over high-intensity lights on rollers so all of the egg can be viewed.

Chalaza
The yolk is anchored to the white by tiny strands of egg white called chalaza. The more obvious and prominent the chalazae, the fresher the egg.