The Art of Freeze Drying

There is one fact about Chef Soraya bowls that sets us apart from the rest, and you may not even realize it! Our ingredients are all freeze dried! They are all freeze dried first and then combined separately according to our recipe. So that means first time the ingredients interact with each other is when they’re cooked by you! The benefits of freeze dried vs dehydrated food may not be known by everyone, but we chose this process for a reason.

There are several differences between freeze drying and dehydration. While dehydrated foods may appear to be withered and tough, freeze dried foods are crisp and crunchy and generally maintain their original shape. Dehydrated foods also remove less water content, making it weigh more and has a shorter shelf life. Freeze drying removes 98-99% of moisture content while dehydration removes 90-95%. The Dehydration process also tends to break down minerals and vitamins in the food, making it nutritional content slightly lower. Freeze dried foods are known to have nutritional content closest to its original food structure plus smells and flavors generally remain unchanged. Dehydrated foods require high heat and long cooking times while freeze dried foods can rehydrate with warm and cold water and are ready to eat much sooner.

The process of freeze drying began in the Andes mountains. Indigenous people would take vegetables up to high elevations and leave them to freeze for several days. The vegetables lost water content but preserved their nutritional content and were able to be stored as emergency rations. Today, we used freeze dryers, some are as big as entire buildings. Freeze drying is often used in the pharmaceutical and biotechnology fields to extent the shelf life of medicines and organic matter. This process was developed primarily for astronauts and military rations.

To begin freeze drying food, the temperature is lowered and a small amount if pressure is applied in order to allow the water content in the food to freeze and form ice crystals. These crystals then undergo the process of sublimation. This takes place in the drying stage. Sublimation is the phase transition of a substance from a solid to a gas state without passing through the intermediate liquid phase. This means that the ice crystals are essentially vaporized. Sublimation occurs when pressure and low heat is applied over time. This process is repeated until the moisture content in the food is reduced by 98-99%. There is also a secondary drying stage at higher heat. After the vacuum is broken and the material is sealed at the end of the process, your food is now freeze dried.

You may have noticed that freeze dried foods seem to have “pores”. These gaps in the material are the areas where ice crystals had formed and were then sublimated into the air. We love to use freeze dried food for its nutritional content, shelf life, ease to prepare, and unchanged flavor. Freeze dried foods are enjoyed today by astronauts, the military, hikers, adventurous eaters, and anyone who loves a nutritious meal!