Freeze-Dried versus Dehydrated Foods
What are freeze-dried foods and dehydrated foods?
Both freeze-dried and dehydrated foods are favourable for long-term storage. To increase the shelf life of foods, people keep them in a cool (40 to 60 degrees F) and dry (with little to no humidity) place. Freeze-drying and dehydration are food processes that remove moisture from foods, they are lighter and less likely to spoil or rot.
Long shelf life of dried foods
Dried foods such as freeze-dried foods and dehydrated foods are not required to be stored in a fridge because the oxygen and water in them have been removed. That means, they have shelf stability and can be safely store at room temperature in a really long time (most of dried foods can be stored at dry and room temperature places for 15 to 20 years).
They are ideal for quick meals, emergency preparedness, and backpacking. Some people are not able to figure out the differences between the two, but it’s important to understand it to make sure you’re investing the right thing.
Some people call it “Lyophilisation”, this is a professional process of preserving already-cooked or fresh food. The food’s moisture is removed up to 98% while the food’s aroma, flavour, nutritional value, and texture still remain intact. The food will be frozen quickly at low temperatures (it could be -58 degrees F) then placed into a vacuum chamber with lower pressure and a higher temperature of 32 degrees F.
The purpose of the process is to obtain the sublimation, which means it’s for making the ice crystals to evaporate into water vapour while bypassing the liquid form of water. The finished product will be a lot more compact and lighter, making it ideal for backpackers. This process preserves the nutritional content and cell structure of the food so the product is very close to the original form of the food.
Rehydration: Freeze-dried food can be restored to its original form in several minutes just by boiling it with water, cold water would do just fine, but it will take a lot longer.
The final product’s weight is reduced by 90% after being freeze dried. Foods such as vegetables, fruits, and meats are very suited to be treated with this freeze-drying food process as it helps store and preserve them in a long time.
Dehydration or drying process is using heat on the food to make it evaporate, hence removes 98% of the moisture in it. Sun drying, air drying… are some of the drying methods, they have been used over hundreds of years.
Dehydration is the act of removing moisture from the food by heating it slowly at maybe from 115 degrees F to 155 degrees F. The heat is distributed by a fan to circulate the air inside the dehydrator.
Home-made dehydrated foods can be stored from 6 months to a year. The shelf life can be a lot longer if the food is sealed with a vacuum container and stored in cold places.
Dehydrated foods also don’t lose much of nutrients compared to their original forms. Dehydrating is a great choice to store food such as fruits and vegetables from the supermarket your garden if you have a lot of it and don’t want to waste it.
Pros and cons of freeze dried foods and dehydrated foods?
Advantages of freeze-dried foods over dehydrated foods:
- Intact therefore better taste: Because the freeze-drying process involves little use of heat, so the food’s texture, smell, nutrients, and taste, etc. remain basically almost the same. On the other hand, while dehydrated foods don’t lose much flavour, they tend to have a chewy texture and are less flavourful than freeze-dried foods (even though maybe it’s just a slight different.
- Longer shelf life: Because more water is removed during freeze drying, so the food is much drier, that means they food’s shelf life is lengthened. Some can be stored up to 25 years.
- Quick reconstitution: Because the food was already readied before the freeze-drying process so all you have to do is boil them with water in a few minutes. Some freeze-dried foods can even be eaten dry, for example, some fruits, vegetables, and crispy chips need no rehydration.
Advantages dehydrated foods over freeze-dried foods:
- More lightweight: Dehydrated foods are generally considerably lighter than freeze dried food. They are more compact as 98% of the water in them lost to evaporation and shrinking in the meantime, so they’re significantly smaller than their original size and more convenient to be carried around.
- Cheaper and economical: There are less expensive than freeze-drying foods. This is because while the freeze-drying process requires large, complicated, and expensive equipment, dehydrated foods are a lot easier to make and can be done at home, even without any of such equipment at all.