Clarence Birdseye and Frozen Food

On August 12, 1930, Clarence Birdseye was granted a patent for his method for quick freezing food. An excerpt from the article:

"On August 12 of the year 1930, U.S. Patent No.: 1,773,079 issued to Clarence Birdseye for "Method of Preparing Food Products". The '079 patent was for an invention that started the frozen food industry. The invention was a process for mass producing frozen food, which when thawed, tasted like fresh food. In contrast, the frozen food of the time was unpalatable to say the least. When thawed, it would be mushy and/or grainy and dry and often having a peculiar taste.

The impetus for Birdseye's invention was his experience in Labrador, which started in 1912 when he spent six weeks along the Labrador coast on a hospital ship. He later returned to Labrador for an extended period of time when he became interested in fur trading. While in Labrador, Birdseye observed how the Inuit quickly froze fish and noted that this frozen fish tasted remarkably fresh when it was thawed. After running experiments on freezing food, Birdseye concluded that when food is frozen slowly, large ice crystals form in the food, which damages the cell structure of the food, thereby changing the texture and taste of the food. In contrast, when food is frozen quickly, much smaller ice crystals are formed that do not damage the cell structure of the food.

After returning to the United States, Birdseye continued to think about frozen food. Finally, in 1923, Birdseye started his own frozen-fish company, Birdseye Seafood, in New York City. He developed his own apparatus for freezing and packaging fish, which he obtained a patent for in 1924 (U.S. Patent No.: 1,511,824). In the '824 patent, Birdseye disclosed that: "[i]t is also highly preferable to bring about the freezing of the fish in the shortest possible time, in order that as has been proved by extensive experiments, and as is recognized in actual commercial practice, the fish will retain its original fresh appearance in color, shape, and also its original texture....". In the Birdseye apparatus, cleaned and fileted fish were held in a special frame within a holding container that was submerged in a refrigerating tank containing a calcium chloride brine. Once the fish filets were frozen into blocks of ice, the fish blocks were removed from the refrigerating tank and the frame, wrapped in wax paper or other type of packaging and then stored in an insulated shipping container, which Birdseye also patented (U.S. Patent No.: 1,527,167).

​While Birdseye Seafood made a number of technological advancements, including the inventions of the '824 and the '167 patents, additional development was needed. However, time and money ran out. By the beginning of 1924, Birdseye Seafood was bankrupt. Undaunted, Birdseye and his wife sold their life insurance policies and used the money to start a new company, the General Seafood Corporation, in Gloucester, Massachusetts. For additional capital, Birdseye brought in wealthy Wall Street investors.

With additional funding and more time, Birdseye was finally able to develop a commerically viable process for mass producing frozen fish filets. This was the process of the '079 patent. In its most basic form, the process consisted of placing a fish filet in a carton in which it was to be sold and then pressing the carton containing the fish filet between two metal plates that were cooled to between -20 and -50ºF. The compression by the plates removed air from the carton and the cooling of the plates would freeze the fish filet into a block of ice. According to the '079 patent, it would take about 75 minutes to freeze the fish filet into a block of ice. In a preferred embodiment, the metal plates took the form of opposed metal conveyor belts."