What are freeze dried meals?

The individual meal packs that we sell at Trek N Tramp typically contain freeze dried meals sourced from Back Country Cuisine (a New Zealand company based in Invercargill) for breakfast and dinner. A fairly typical question is what exactly is freeze drying?

In simple terms it pretty much works as follows.

Firstly the meal to be freezer dried is prepared and fully cooked by Back Country Cuisine in their plant in Invercargill. After the cooking process is complete the product is snap frozen. The freezing process is extremely rapid and the temperature of the cooked product is reduced to well below zero degrees in a few seconds. If you like to get technical the rapid freezing prevents the formation of large ice crystals which would damage the nutrients in the meal.

Following the blast freezing the air pressure is reduced to a near vacuum. When this occurs frozen water content of the meal begins to sublimate. Sublimation is the process of water turning from a solid (ice) into a gas (water vapor) without passing through the liquid state. The result is that virtually all of the moisture (water) is removed from the product. Once this process is completed the product is packaged and is ready for use.

There are two really cool things about freeze dried meals. Firstly they are very light which is important when you are carrying them in the outdoors. Secondly they don’t require any refrigeration and have a shelf life of several years.