Food preservation is as old as mankind
Being able to preserve food to use at a later time has allowed humans to form communities.
Food, by its nature, begins to spoil the moment it is harvested. To survive, our early ancestors had to find a way to make that food last through the lean times. In frozen climates, they froze meat on the ice; in tropical climates, they dried foods in the sun. These early methods of food preservation enabled ancient man to put down roots, live in one place and form communities. They no longer had to consume the kill or harvest immediately, but could preserve some for later.
In ancient times, the sun and wind would have naturally dried foods. Evidence shows that Middle East and oriental cultures actively dried foods in the hot sun as early as 12,000 B.C. The Romans were particularly fond of any dried fruit they could make.
In the early 1900s, natural draft dehydrators were created to dry fruits, vegetables and herbs in areas that did not have enough strong sunlight for drying. These early dehydrators were designed with fire pits on the bottom and exhaust vents at the top. As the fire heated the air, it was carried upwards creating the critical air flow and low humidity that is essential for dehydration.
Freezing was an obvious preservation method in the appropriate climates. Any geographic area that had freezing temperatures for even part of a year made use of the temperature to preserve food. Less than freezing temperatures were used to prolong storage times. Cellars, caves and cool streams were put to good use for that purpose.
In America, estates had icehouses built to store ice and food on ice. Soon the “icehouse” became an “icebox.” In the 1800s mechanical refrigeration was invented and was quickly put to use. Also in the late 1800s, Clarence Birdseye discovered that quick freezing at very low temperatures made for better tasting meats and vegetables.
Canning is the newest of the food preservations methods. Canning is a process by which foods are placed in jars or cans and heated to a temperature that destroys microorganisms and inactivates enzymes. This heating and later cooling also forms a vacuum seal. The vacuum seal prevents other microorganisms from recontaminating the food.
Canning was pioneered in the 1790s by the Frenchman Nicolas Appert. He discovered that the application of heat to food in sealed glass bottles preserved the food from spoilage. In 1800, Napoleon offered an award of 12,000 francs to anyone who could devise a practical method for food preservation for armies on the march. Appert won the award.
Appert had found a new and successful method to preserve foods, but he did not fully understand it. He thought that the exclusion of air was responsible for the preservations. It was not until 1864 when Louis Pasteur discovered the relationship between microorganisms and food spoilage that it became clear.
Just prior to Pasteur’s discovery, Raymond Chevalier-Appert patented the pressure retort (canner) to can at temperatures higher than 212ºF. However, not until the 1920s was the significance of this method known in relation to the prevention of botulism in low acid foods.
Home food preservation has taken an upturn in popularity in recent years as more people are concerned about where their food comes from and how it has been processed. As improvements in equipment are made, it becomes easier and more convenient to preserve food at home. Michgan State University (MSU) Extension has a recently updated series of food preservation bulletins available at the bookstore that can be downloaded for free . Additionally, many MSU Extension educators will be offering food preservation classes throughout the state this summer.