The plasma makes up about two thirds of
cattle and pig blood and contains dispersed
proteins, about 7% by weight. Albumin is the
protein that causes blood to thicken when
heated above 167ºF/75ºC .
Shellfish Organs The liver and eggs of
crustaceans, and the sexual tissues of sea
urchins have the same advantages and
disadvantages as liver, and thicken and
coagulate at much lower temperatures. They
should be added carefully to a sauce that has
first been allowed to cool well below the boil.
Cheese and Yogurt These cultured milk
products differ from the other protein
thickeners in that their casein proteins have
already been coagulated by enzyme activity
and/or acidity. They’re thus unable to develop
a new thickness by being heated with a sauce.
Instead, they lend their own thickness as
they’re mixed into the sauce. They’re best
subjected to only moderate heat, since