Salt Cod Bountiful cod was one resource that attracted Europeans to the New World, where 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 several changes of water. Perhaps the best-known preparation is the Provençal brandade, a paste made by pounding the shredded poached fish along with olive oil, milk, garlic, and sometimes potato.
Salt Herring Herring and their relatives may be up to 20% fat by weight, and are therefore susceptible to becoming rancid when exposed to the air. Medieval fishermen solved this problem by barreling the fish in brine, where they would keep for as much as a year. Then sometime around 1300, the Dutch and northern Germans developed a quick gutting technique that left in place a portion of the intestine rich in digestive enzymes (the pyloric caecum). During one to four months of curing in a moderate brine (16–20% salt), these enzymes circulate and supplement the activity of both muscle and skin enzymes, breaking down proteins to create a tender, luscious texture and a wonderfully complex flavor, at once fishy, meaty, and cheesy. Such herring are eaten as is, without desalting or cooking.
Two particularly prized types of cured herring are the lightly salted Dutch groen and maatjes, or “green” and “maiden” herring, which traditionally broke the win-ter-long diet of hard-cured beef and fish. Because all lightly cured fish must now be prefrozen to rid them of parasites (p. 186), these formerly seasonal delicacies are now made and enjoyed year-round.