Understanding The Process of Freeze Drying Food, by Thomas Baldrick

Monday, Aug 26, 2013

To understand freeze drying there is less to digest than you might think. If you’re into survival, freeze dried food is your friend. It’s a good friend because you’ll enjoy it and feel good having it around. Like a weapon, a partner or a loyal dog, it serves as your trusted companion… always there for you when you need it most. Now let’s explain the process of freeze drying food and understand how this friendship begins.

What is Freeze Drying?
While today’s freeze drying industry is powered by some really smart people and super high tech equipment, the concept remains fairly simple and straightforward.
The process of freeze drying food removes moisture from a frozen material in a way which allows it to retain the benefits of its original form, aroma, taste, texture, and nutritional value.
Freeze drying is the most natural proven approach to food preservation. It delivers positive results for easier and extended food storage guaranteed to last for decades.

Why Freeze Dry?
There are three main reasons behind the strategy of freeze drying food. It is an exit, maintain, and return strategy.
1. Exit: You completely remove water in foods from A to Z (apricots to zucchini).
2. Maintain: You keep in the taste, nutrients, and composition of the food.
3. Return: You open the food sealed and preserved in cans or packets when you want or need it most.

Freeze drying food fights bacteria and other microorganisms because just like human beings, they require water to survive.

Freeze-drying also significantly lessens a food’s total weight. Most food is largely made up of water. Removing the water makes the food up to 90% lighter and therefore easier to lift and transport near or far.

Who Started Freeze Drying and When
The process of freeze drying food is built upon the methods of ancient civilizations. There are traces of freeze drying food dating back to 9th century Asia. Ancient Indians high in the Andes Mountains were also said to practice their own form of freeze dried foods.  

In 1813, William Hyde Wallaston pulled the freeze drying process forward in a big way with a very cool discovery. In a presentation to the Royal Society in London, he introduced a procedure known as sublimation.
Wallaston detailed his work for developing the fundamental process of directly converting liquid in a frozen (solid) state to a gaseous state (vapor). Sublimation is just like evaporation. It is able to occur when a molecule gains enough energy to break free from the others around it.

During World War II, there was tremendous need for human plasma due to the alarming high rate of battle related casualties. With the help of emerging developments in vacuum systems and mechanical refrigeration during these times, freeze drying was used to assist in improving the storage of human plasma.  

Later, the U.S. Military again turned to freeze drying as a solution. Freeze dried foods were introduced to Special Forces as a way of improving upon its bulky and bland C-Rations and other foods given to the troops. NASA did the same for feeding its astronauts on space missions where weight and space are critical factors for success and survival.   

Freeze Dried Foods are now a staple in the U.S. Military and Space programs as well as throughout American society. As much as many people love to bash the U.S. Government for its inefficiencies and corruption, the government rightly deserves credit for its efforts in the advanced freeze dried foods we have around the world today.

Beyond the food industry, a number of other sectors have warmed to the idea of the freeze-drying process. It is commonly used by florists and taxidermists, museums and insurance companies for repairing and restoring water-damaged items, and is an increasingly important factor in the pharmaceutical industry.

How the Freeze Drying Process Works
Rooted in Wallaston’s Sublimation procedure, modern freeze drying machines consist of the following components. A freeze-drying chamber, shelves connected to heating units, a freezing coil attached to a refrigerator compressor, and a vacuum pump.

Successful freeze drying is done in a 3-step process which takes many hours or even days. The food is freeze-dried in a system which converts ice directly into water vapor. This skips the liquid phase completely. Freeze drying bypasses the need for applying high-temperature heat necessary for creating the evaporation process.
1. Cooked or fresh food is flash frozen solid. This locks firmly into place the shape, nutritional value, taste, texture, aroma, and appearance of the food.
2. The frozen food is then placed into a vacuum chamber. A cold condensing surface helps to attract the ice vapor. Inside the temperatures are as low as minus 50 degrees Fahrenheit. Usually roughly 98% of the moisture from the food is removed through evaporating the ice.
3. The freeze dried food gets sealed by securely placing it into oxygen and moisture and oxygen barrier packaging. The preserves the food’s freshness until you are ready to open it.
After the freeze drying process it shows its superior value and versatility for survival planning and long-term food preservation needs.

In essence, freeze dried food offers the best of both the frozen and dehydrated food worlds. It removes the moisture and spoiling, but maintains the beauty and convenience of looking, smelling, and tasting fresh.  The process of freeze drying makes it an ideal solution for those who see the common sense and realistic value of having survival food on hand when you need it.

Knowing the benefits of the freeze drying process, I'm sure you can see the importance of having freeze dried food in your survival food plan.

About The Author: Thomas Baldrick is an executive manager at Freeze Dry Guy, a supplier of freeze dried food and other emergency preparedness items. The company was started in 1970 by a U.S. Army Special Forces veteran. They've been a SurvivalBlog advertiser for six years without any complaints from customers.


Copyright 2005-2012 James Wesley, Rawles - SurvivalBlog.com All Rights Reserved