Freeze-drying – vs – Dehydrating
What’s the difference?
Dehydrated food and freeze-dried food are both methods of food preservation that remove moisture from the food to extend its shelf life. However, they differ in the way that they remove the moisture and the resulting texture and flavor of the food.
Dehydrated food is made by removing moisture from the food through a process of evaporation. This can be done using a dehydrator, an oven, or even the sun. The food is typically sliced or chopped into small pieces and then placed in the dehydrator or oven at a low temperature for several hours. The process removes the water from the food, leaving it dry and often crispy.
Freeze-dried food, on the other hand, is made by removing moisture from the food through a process of sublimation. This involves freezing the food and then placing it in a vacuum chamber, where the ice is removed through a process of evaporation without ever thawing the food. The resulting product is lightweight, crunchy, and retains most of its original flavor and nutrients.
The main difference between the two methods is that dehydrated food retains some moisture, while freeze-dried food is completely dry. This means that dehydrated food is usually heavier and bulkier than freeze-dried food, making it less ideal for camping or backpacking trips. Additionally, the texture of dehydrated food is often chewy or leathery, while freeze-dried food is crispy and crunchy.
Another key difference between the two methods is the shelf life of the resulting product. Freeze-dried food has a much longer shelf life than dehydrated food, typically lasting up to 30 years if stored properly. Dehydrated food, on the other hand, typically has a shelf life of around 1-2 years.
When it comes to nutritional value, both dehydrated and freeze-dried foods can be healthy options. However, it’s important to note that the drying process can cause some nutrient loss, particularly with dehydrated foods. Freeze-dried foods tend to retain more of their original nutritional content, making them a slightly better option in this regard.
In summary, while dehydrated and freeze-dried foods are both methods of food preservation that remove moisture from the food, they differ in the way they do it and the resulting texture, flavor, and shelf life of the food. Dehydrated food is heavier and bulkier, has a shorter shelf life, and a chewy texture, while freeze-dried food is lighter, has a longer shelf life, and a crispy texture.
These fruit chews make it easy to see the process that foods go through during the freeze drying process:
Before the freeze drying process:
Shortly after the vacuum starts:
A little further into the process: