In World War II, there was a problem. Many of the soldiers needed critical serums to overcome the illnesses and injuries of the war, but the serums were delicate and time sensitive. Many of the serums had spoiled by the time they arrived at the medical officers and were not viable for the soldiers. The government needed a way to get the power of the medicine to the men in the field without making it in the field.

To assist in this process a new technology was activity pursued. This new development promised to bypass the transformation of solid to liquid to gas and go straight from one end to the other. Then the pressure was to be shifted so that the frozen water in the compound would turn into a gas and leave the rest stable and solid. The process became known as freeze drying.

The commercialization of freeze drying began during World War II and has continued into today. It has been both a part of commercialized products and specialized needs. It has been used for entrepreneurs who have developed novelties like MonaVie and Dipping Dots for general consumption and the food industry has benefited from it all and it has been used to make astronaut food.

The first step in freeze drying is the initial freezing. It takes the product (food or medicinal) and drops its temperature rapidly and seals it all in. This is accomplished by the aid of liquid nitrogen, solid carbon dioxide, or methanol. More than just quick cooling, however, this process is designed to bring it below the triple point in temperature and pressure (the point where all three stages can exist simultaneously). The material is then prepared for the next stage – drying.

In the drying stage there are two parts – the primary drying stage and secondary drying stage. The primary drying stage is a balance of low pressure and slightly warmer temperature. As the pressure lowers to only a few millibars, the temperature is raised enough for the water to sublime – which is the process of transforming from a solid to a gas without hitting the intermediate liquid phase. This allows for a vacuum to assist in removing the water molecules without the material becoming re-hydrated or unfrozen. Once the initial water has been collected, the secondary phase begins. There the temperature is again modified to be a little higher than before and the water that never froze in the first place is removed.

This process has allowed more food and medicine from around the world to be transported anywhere with little to no decomposition or spoiling. The technique is especially handy when dealing with delicate fruits like the acai berry from South America. While the berry is loaded with antioxidants and healthy nutrients, it lasts only a couple of days off the tree. Instead of being limited to local consumption, freeze drying has allowed this berry to be preserved and later added to drinks and foods that are consumed world wide by a variety of peoples and cultures.