60ºC. Some dense-fleshed fish, including tuna
and salmon, are especially succulent at 120ºF,
when still slightly translucent and jelly-like.
Creatures with a large proportion of
connective-tissue collagen — notably the
cartilagenous sharks and skates — benefit
from higher temperatures and longer cooking
to turn it into gelatin, and can be chewy unless
cooked to 140ºF/60ºC or higher. Some
molluscs are also rich in collagen and benefit
from long cooking (p. 225).
Why Some Fish Seem to Dry Out Faster
Than Others
One puzzling aspect of fish cooking is the
fact that different fish can have
surprisingly different tolerances for
overcooking, despite similar protein and
fat contents. Rockfish, snappers, and
mahimahi, for example, seem more moist
and forgiving than tuna or swordfish,
which tend to become firm and dry very