On Food and Cooking

in diameter.
Cuticle and Color The hen’s finishing touch
on her egg is a thin proteinaceous cuticle. This
coating initially plugs up the pores to slow
water loss and block the entry of bacteria, but
gradually fractures to allow the chick to get
enough oxygen. Along with the cuticle comes
color, in the form of chemical relatives of
hemoglobin. Egg color is determined by the
hen’s genetic background, and has no relation
to the egg’s taste or nutritional value.
Leghorns lay very lightly pigmented “white”
eggs. Brown eggs are produced by breeds that
were originally dual-purpose egg and meat
birds, including Rhode Island Reds and
Plymouth Rocks; New Hampshire and
Australorps hens were bred for intensive
brown-egg production. Chinese Cochin hens
paint their eggs with fine yellow dots. Thanks
to a dominant trait unknown in any other wild
or domestic chickens, the rare Chilean
Araucana lays blue eggs. Crosses between