Whats Going On?
dont I just let the eggs boil?
boiled egg may be part of the breakfast tradition in
many households, but boiling is a miserable way to treat an egg.
Because high heat toughens protein, the major constituent of eggs,
boiling quickly changes an egg from a tender gel to a resilient
might be surprised to learn that egg white solidifies between 140º
F and 149º Ffar below waters boiling point. Egg yolk
coagulates between 149º F and 158º F, a temperature higher than
egg whites because the yolk's protein structure is different and
not as sensitive to heat. When an egg is in boiling water, the intense
heat promotes extensive protein bonding, so it solidifies quickly
and changes to a texture thats best described as rubbery.
Cooked gently, eggs are firm but still tender. They not only taste
better, theyre easier to digest.
Gardiner and Sue Wilson, The
happens when egg white cooks?
proteins are long molecules, made up of chains of amino acids linked
together. In a raw egg, these proteins are curled and folded to
form a compact ball. When you cook an egg, these proteins uncurl
and form new bonds with one another. The longer you heat the proteins
and the higher the temperature, the tighter the proteins will bond
to each other. The tightness of these bonds determines whether the
eggs are cooked just rightor overcooked. Our method for hard
cooking eggs heats the eggs slowly, making for loose bonds among
the proteins and tender, rather than rubbery, egg whites.
can I stop the yolk from turning green?
hard-cooked eggs into cold water helps keep the yolk from turning
green. The green-gray color (and the whiff of sulfur smell that
often accompanies it) comes from the reaction of iron in the egg
yolk and sulfur in the egg white. When heated, the two can combine
to make green-gray ferrous sulfide and hydrogen sulfide gas. To
avoid getting a green yolk, cook your eggs just long enough to reach
the desired doneness—no more. And quickly plunge the cooked
eggs into cold water to stop the cooking process and minimize the
people make a pinhole in an egg before they cook it. Why?
may want to use a pin to poke a small hole in the large end of the
egg before you boil it. The hole lets air escape from the air pocket
at the large end of the egg, giving you a hard-cooked egg that is
rounded, rather than flat, on the large end. Some say that water
leaking in through this hole makes eggs easier to peel, but we havent
noticed any difference in “peelability.”
are eggs sometimes hard to peel?
an egg is very fresh, the cooked egg white may stick to the membranes
inside the shell, making the egg difficult to peel. As an egg ages,
the white becomes more alkaline and loosens its grip on the membrane.
For the most peelable eggs, buy eggs a week to ten days before you
hard cook them.
make any egg easier to peel, crack the shell all over by rolling
the egg between your hands. This breaks the shell into tiny pieces.
Its easier to get each tiny piece free of the white than to
try to pull off a big chunk.