In the previous articles of this series, I have shown how salt was both essential and strategic to early humans. Without ingesting and metabolizing salt, humans (as well as all mammals) could not survive, and salt proved integral to the human food web as a preservative. Salt was also key to warfare in that gunpowder contains potassium chloride.
Until the Industrial Revolution, wars were fought for control of salt sources, cities were located close to salt, and all production from sea water, brine wells, and mines was a major industry. Today, however, salt is no less important in food, but is not in short supply and considered far less strategic. The decline of salt’s importance resulted from three basic factors.
First, advances in transportation and distribution. Humans went from hunters and gathers on foot to mobilizing on horses and mules, boats, trains, cars and planes. Each of these advances allowed food to be moved from source to user more quickly, reducing the need for salt preservation at the source. Though some people had come to think of salt as a part of food, most were pleased to “add salt to taste” rather than taste salt already added.
Today, some stores define “local produce” or “fresh produce” as being produced within seven hours transport time from the store. This means that, in theory, champagne grapes from south Peru can be called local in Boulder, Colo., because the flight time is just under seven hours. So even though advances in transportation have reduced the need for salt, we still might want to take some advertising claims about “fresh” or “local” produce with a grain of salt.
Second, the discovery of preservation by canning. In the late 1700s, an obscure French confectioner named Appert believed that placing his candies in sealed glass jars and then heating the jar destroyed the agents of rot, which he called ferment. Initially, Appert pursuaded Napoleon to use his seal-and-heat system to take meat and vegetables in sealed glass jars with the French Navy, and the experiment was met with great praise, the soldiers claiming the produce from the jars tasted “fresh and flavorful.”
Appert wrote a book in 1809 titled, “The Art of Preserving All Kinds of Animal and Vegetable Substances for Several Years,” which was widely read, and translated into several languages, including English, after which an Englishman, Peter Durand received a process patent for preserving food in nearly the exact manner Appert described in his book. But it was Bryan Donkin, a British industrialist of the same period who came up with the process of using tin cans as the container for the preserved foodstuffs.
In 1809 Donkin founded Dartford Iron Works and later Donkin, Hall, and Gamble, the first British canning plant, located in London. The latter provided the full set of provisions for the arctic expeditions of William Edward Perry in the 1820s, by which time canned food had moved from a speciality process devoted to the military or the infirm, to a flourishing industry that can be credited, at least in part, with the fading, and eventual disappearance of the European Atlantic salt fish industry.
The third and final factor that diminished the role of salt in food preservation was the mastery of various cooling and freezing, techniques. It was understood that meat and fish harvested in northern Canada could be gutted, cleaned and naturally quick-frozen, then shipped some distance without spoilage.
Clarence Birdseye, a food and feed processor did not like the practice of using ice as a preservative because ice was messy. It melted, re-froze selectively, and finally became an undesirable medium for bacteria that introduced elements of rot, or ferment.
In 1925, Clarence Birdseye moved to East Coast of the U.S. in Massachusetts and with entrepreneurial flair started a frozen seafood company. Birdseye learned in Northern Labrador that rapid freezing was the best way to freeze fish and other food substances, because the faster a substance froze, the smaller the size of the ice crystals, and thus only slight damage was done to the cells and tissues of the substance. Larger crystals that formed from the slow and inconsistent freezing of ice caused the produce to be limp upon thawing.
Birdseye stared General Foods. By 1910, General Foods did 99 percent of the frozen fish processing on the East Coast and is credited with at least 250 patents related to dozens of devices and machines that enabled fast freezing, rapid packaging, and refrigerated distribution. By 1928, Birdseye and General Foods were producing over one million pounds of frozen food for distribution all over the U.S., and this marked the end of the “Age Of Salt” for food preservation. ❖