At this point in time, it’s pretty obvious what we sell. We sell freeze dried food. We always talk about Fuel Your Preparation and how 98% of the residual oxygen has been removed which contributes to the 25-year shelf life. But have you ever wondered how it’s done? What exactly is the freeze drying process? In this article let’s talk about freeze dried food and the process on how it’s made.
Brief History of Freeze Dried Food
Before we start talking about freeze drying process, let’s do a brief history lesson. One of the first people freeze and store food were the Chinese. They stored food in ice cellars and have been known to be the first to freeze food outside of winter as early as 1000 B.C. The Greeks and Romans were also known to freeze their food. They would retrieve ice and snow from the top of the mountains and kept their food and drink cold in underground cellars, protected by wood and straw.
Chuño – The First Freeze Dried Food
The grandfather of freeze dried food – Chuño
The people in the Tiwanaku culture period, pre-dating the Inca empire, may be credited as the first people to utilize the freeze-drying process and they’ve been at it since approximately 400 B.C. Thanks to the freezing temperature of the Andes, the chuño was born. These small potatoes were left for three nights, exposed to the sun, trampled by foot, and peeled. This process eliminated the water and then they’re exposed again to the cold for another two nights to complete the crude freeze drying process. Once dried, they can last a long time even with minimal care. No wonder it’s still a staple food in Argentina, Bolivia, Chile, Peru, and various countries in South America.
Freeze drying in the Modern Age
In 1965, astronauts Virgil I. “Gus” Grissom and John W. Young were the first to consume freeze dried food in space
Now let’s talk about freeze drying in the modern age. Toward the end of the 1880s the basic principles of freeze drying were already understood and used in a laboratory scale. Richard Altmann freeze dried organs and tissues for historical examination in Leipzig in 1890. In World War II, freeze drying was used to preserve blood being delivered from the US to Europe. Instant coffee was invented and patented in 1880 but Nescafe was the first to use freeze dried coffee beans in 1938. The use of freeze dried coffee beans has become the industry standard.
Freeze dried food started to gain momentum in the 1950s. The first meal in space was eaten by John Glenn aboard Friendship 7 in 1962 but the first freeze dried food eaten in space was in 1965. Astronaut John Young carried two meal packages in Gemini 3 to sample on their 5-hour mission. Now freeze drying has proven to be important not just in the food industry but in the pharmaceutical and medical industry.
Freeze Drying – The Process
Freeze dried food is the best survival food
Here comes the good part – Freeze dried food and how it’s made. Freeze drying is mainly a two-step process of rapid freezing and subsequent dehydration. To preserve its nutrients, flavor, etc., food is fast-frozen by placing the item between two hollow plates that contain a refrigerant liquid in a tightly-sealed chamber. While the food is being frozen, a high-powered pump creates a vacuum in the chamber. Then the refrigerant liquid in the hollow plates is replaced with warm gas, which converts the ice in the food directly into vapor. The process of converting solid (ice) to gas without passing through the liquid phase is called sublimation.
The dehydration process takes about 20 hours. Part of the reason Freeze Dried Food is more expensive is due to the long preparation and packing times and considerable electricity used in the process.
Freeze Dried Food – From Past to Present
There you go. Pretty simple right? Now you know a little more about freeze drying and freeze dried food. From the ancient Incas to modern day astronauts, freeze dried food has been an important part of our lives. Next time you open a pack or a can of Fuel Your Preparation, think about history and technology behind that delicious meal that you’re consuming.