On Food and Cooking

Target Temperatures In meat cooking, the
critical temperature is 140ºF/60ºC, when the
connective-tissue collagen sheath around each
muscle cell collapses, shrinks, and puts the
squeeze on the fluid-filled insides, forcing
juice out of the meat. But fish collagen
doesn’t play the same critical role, because its
squeezing power is relatively weak and it
collapses before coagulation and fluid flow
are well underway. Instead, it’s mainly the
fiber protein myosin and its coagulation that
determine fish texture. Fish myosin and its
fellow fiber proteins are more sensitive to
heat than their land-animal counterparts.
Where meats begin to shrink from coagulation
and major fluid loss at 140ºF/60ºC and are dry
by 160ºF/70ºC, most fish shrink at 120ºF/50ºC
and begin to become dry around 140ºF/60ºC.
(Compare the behaviors of meat and fish
proteins in the boxes on pp. 152 and 210).
In general, fish and shellfish are firm but
still moist when cooked to 130–140ºF/55–