On Food and Cooking

the standard treatment was to split and salt the
fish, and lay them out on rocks or racks to dry
for several weeks. Nowadays cod may be
hard-cured for 15 days to saturate the flesh
with salt (25%), then held without drying for
months. During that time, Micrococcus
bacteria generate flavor by producing free
amino acids and TMA; and oxygen breaks up
to half the very small amount of fatty
substances into free fatty acids and then into a
range of smaller molecules that also
contribute to aroma. The final artificial drying
takes less than three days.
Salt cod remains a popular food around the
Mediterranean as well as in the Caribbean and
Africa, where it was introduced during the
slave trade. Scandinavia and Canada are still
the largest producers. White pieces are
preferred to yellowish or reddish ones, the
colors being indicators of oxidized or
microbial off-flavors. Cooks first reconstitute
and desalt it by soaking it for hours to days in