From backpackers to astronauts, freeze-dried meals have been a staple for years, providing a quick and easy meal when cooking just isn’t an option… or at least not a convenient one.
But where did this method come from? Can you freeze-dry other things besides food? And how the heck can a pack of freeze-dried fettuccine alfredo with chicken have a shelf life of 10 YEARS?! These are the questions that haunt me.
WHAT IS FREEZE-DRYING?
The modern form of freeze-drying is a three-step process. It starts with freezing (shocking, right?) to preserve its physical form, then sublimation to remove 95% of the water using a vacuum, then finally, adsorption or secondary drying is done to remove any ionically bound water molecules.
WHO CAME UP WITH THIS STUFF?
It began with the Incas high in the Andes Mountain, was used to save lives during WWII, and went mainstream when NASA developed freeze-dried ice cream.
It dates back all the way to the 15th century when the Incas would store their food in the mountains above Machu Picchu, according to Freeze-Dry.com. Freezing temperatures in the high-altitudes of the Andes mountains are almost guaranteed at night, so they would bring their potatoes up the mountains and leave them under a cloth to freeze. In the morning, villagers would walk on top of the cloth to remove the water. The low air pressure slowly vaporized the water inside and created a lightweight food source that could last for years and feed communities in times of drought or crop failure.
During WWII, modern forms of freeze-drying were developed when blood transported from the U.S. to Europe for wounded soldiers would spoil from lack of refrigeration. First, they had to separate the four components that make up the blood - red blood cells, white blood cells, platelets, and plasma. Plasma is made of mostly water and carries nutrients to cells across your body, but also contains clotting proteins. This was essential for medics on the battlefield as they could prevent further blood and oxygen loss from wounded soldiers by transfusing them with the plasma.
Ok, I know what you’re thinking… Do they not have to match up blood types?
NOPE! This process allowed them to separate the plasma from the red blood cells and render it to a chemically stable and usable state, so the need to match up types is unnecessary. Today, military medics continue to use freeze-dried plasma to save wounded soldiers on the field.
From there, the freeze-drying process became an innovative technique for preserving food, pharmaceuticals, and plenty of other materials.
Once NASA came out with their freeze-dried ice cream, it was game over. The freeze-drying process went mainstream and caused a surge in the production of freeze-dried foods and products. This shift transformed society's understanding of “shelf life” and introduced products that are now staples for thru-hikers, astronauts, and even you! (yeah, those Sea Monkeys and Triops you used to get as a kid were totally freeze-dried)
Over the last two years, professors Michael Menze and Jonathan Kopechek and P.h.D. candidate Brett Janis at the University of Louisville have been experimenting with freeze-drying red blood cells. Their process turns red blood cells into a powder, giving them a longer shelf life and the ability to be easily transported and stored without refrigeration. The powder can be mixed with sterile water and theoretically transfused into the recipient just like a normal blood transfusion.
Still a little skeptical? Yeah, same. So far, this process of transfusing the rehydrated red blood cells into a living body has only been tested on rats—which have all survived. Their next step would be to test on larger animals and then humans in the coming years.
The U.S. is involved in military operations in over 150 countries, many of which don’t have the established infrastructure as they do in Afghanistan, according to Military.com. When a soldier is injured and possibly hemorrhaging in the more remote areas, they have a higher chance of survival if they receive the blood quickly.
This innovation would be HUGE, not just for the military, but for health professionals and countries where refrigeration and/or electricity are not prominent. Think about it, ambulances can save space on their vans and as EMS Dr. Dave Duncan said, “red blood cells are like a little time machine.” When someone is bleeding and you transfuse red blood cells into their system, you buy time - time that can be the determining factor between life and death.
FROM MOUNTAINS, TO THE BATTLEFIELD, TO SPACE AND BACK
So, it started with potatoes in the Andes, evolved into a life-saving military innovation, fueled the astronauts, and is now freeze-dried meals that can be found in just about every backpack from the Appalachians to the Cascade Range! Since freeze-dried meals and snacks contain 95% less water, they save weight and space in your pack - two necessities for most multi-day trekkers.
The modernization of the freeze-drying process has and will continue to change the way we think about food, pharmaceuticals, blood and so much more. I guess we’ll just have to wait and see what the future holds!
But wait… if we’re changing the chemical structure of freeze-dried foods, are they still good for you to eat? Find out in “Would You Eat 37-year-old Beef Stew?”
How has the freeze-drying process affected you personally?
Have you ever tried a freeze-dried meal or benefited from freeze-dried plasma?
Go ahead and comment below with your experiences!