Cod liver oil is slick in many ways!

An Inuit vigorously paddles a sealskin kayak as he approaches the fishing area where he hopes to make a catch with his harpoon. This Inuit, however, is only a mannequin clothed in an authentic parka; he and his single scull boat are exhibits in the Maritime Museum located in the center of the English city of Hull. The museum’s somewhat antiquated collection recalls the days when Hull was still an important fishing town where fish from nearly all the seven seas were landed. Seven Seas, a company founded to process the cod liver oil so highly recommended by doctors and so feared and loathed by children, is favorably situated across from the docks of Hull.

“Today, however, we work with raw oil that comes in containers weighing around 25 tons that are shipped in mainly from Iceland, but also from small companies in Norway,” says Charles Craven, Head of Regulatory Affairs at Seven Seas. The cod liver oil is extracted by the company from the approximately four-kilogram livers that are removed from the coveted codfish. Teams on ships fillet the fish right after the catch is over. The fillets are immediately shock-frozen, but the livers are placed in cold saltwater, since they would crumble if they were subjected to the shock-freezing process.

After they reach shore, the livers are sent through a large cutting machine and then immersed in water heated to a temperature of around 60 degrees Celsius, which causes the raw cod liver oil to settle on the water’s surface. This oil actually accounts for 60 percent of a cod liver’s weight. “It’s the energy storage unit of the fish,” Craven explains, adding that there are government quotas for the number of cod that may be caught, as well as regulations governing the times of the year when they can be fished for. “The composition and quality of the raw oil varies depending on the season and the fishing ground in question as well as its depth,” says Craven.

The received oil is deep brown in color, sometimes with a tinge of red. In any case, it’s murky and its smell can turn one’s stomach. “This is what we ultimately produce from it,” says Martin Barnard as he sets down a phial containing something that looks like liquid gold, and whose odor bears only a trace of the oil’s original smell. Barnard, who manages the refining process, has detailed knowledge of every station in the company’s ultra-clean and highly automated facility.