On Food and Cooking

together into dense particles, and the sauce
becomes grainy and thins out again. Most
animal proteins coagulate beginning around
140ºF/60ºC, but this critical point can vary, so
there’s no substitute for careful monitoring of
the sauce’s consistency. Once the sauce has
thickened, careful straining can remove the
few particles that may have formed.
In all protein-thickened sauces, the cook
must take care when mixing the hot sauce
with the cool thickener. It’s always safest to
stir some of the sauce into the thickener, thus
heating the thickener gently and diluting it,
and then add that mixture to the rest of the
sauce. If the thickener goes directly into the
sauce, then some of the thickener will get
instantly overheated and coagulate into grainy
particles. Cooks sometimes work pastes of
liver or shellfish organs into butter and then
chill the mix. When a chunk of the mix is
added to the sauce, the butter melts and
slowly releases the thickener into the sauce,