readily detects cracks in the shell, harmless
but unappealing blood spots on the yolk (from
burst capillaries in the hen’s ovary or yolk
sac), and “meat spots” in the whites (either
brown blood spots or tiny bits of tissue
sloughed off from the oviduct wall), and large
air cells, all characteristics that relegate an
egg to the lower grades. To determine the
condition of the yolk and white, the egg is
quickly twirled. The yolk’s shadow will
remain indistinct if its membrane is strong
enough and the white thick enough to have
kept it from getting close to the shell. If the
yolk is easy to see, then it’s too easily
deformed or mobile, and the egg is of lower
quality.
Egg Grades
Eggs sold in stores are usually (but not
mandatorily) classified by United States
Department of Agriculture (USDA) grades.