Freeze-dried foods have a number of interesting properties. Let's look at them in detail.
Weight
Freeze-dried fruit, vegetables or meat are very light in weight. Although it may not seem like it, a really big part of fruit, vegetables or meat is water. When the freeze-dryer reduces the proportion of water in the food to the level of one percent, the weight is logically reduced.
Space programmes in particular benefit from this property, where every gram that needs to be put into Earth orbit counts. But such dried food is also a target in the crosshairs of climbers, polar explorers, and others who cannot afford to carry unnecessary water with them.
Shelf life
The absence of water (and good packaging) will ease the decomposition process tremendously. Depending on the execution of the process, the shelf life of various foods can range up to around 20 years.
If you've purchased a package of freeze-dried food from Asia (usually bought through Poland or Germany), you may be wondering why the expiration date is only set for six months to a year from the date of manufacture. This may be partly due to the lack of vacuum packing, but mostly it is mass production, where the manufacturer tries to shorten the process itself, usually beyond what is possible. The resulting product is really crispy and light, but has a higher percentage of moisture because, according to the manufacturer, the customer would not appreciate a longer shelf life. Moreover, in mass production it is desirable that the purchased product expires and the customer has to buy a new one.
Preservation of vitamins and nutrients
The freeze-drying process removes only water from the food. All vitamins and nutrients are preserved, which cannot be said of other drying methods. Because almost the entire process takes place in sub-zero temperatures, there is no risk of losing what we love about fruit, vegetables or meat. An indispensable feature in any ROW kitchen.
The "A" must be accompanied by a "B" and we therefore warn that the freeze-drying process does not completely kill bacteria or mould. Meat in particular needs to be cooked before consumption, whether you brought it from the butcher or took it out of the vacuum pack after 2 years where it was packed after freeze-drying.
Rehydration
Compared to conventional drying methods, freeze-dried foods have some distinctly unique properties. Apart from their durability and preservation of vitamins, they can also be rehydrated, in other words, returned to their original state.
This is an advantage especially for fruit and vegetables, but even freeze-dried ham can be restored to its original state simply by immersion in water. Some foods, such as meat, take back as much water as they need. Others need to be watched (e.g. a banana) to prevent them from getting soggy. Freeze-dried ready meals also do not need to be scooped dry, just use a gentle rehydration method - steam cooker or microwave.
No transfer of smells and tastes
What is also interesting about the drying process itself is that the individual foods do not affect the other foods that are in the freeze dryer with them. Meat, fruit or vegetables can be dried together. We tested this ourselves on a combination of ice cream, bean stew, pineapple, chicken thighs and bananas.
The possibility of shredding
With no water, grinding is almost a joy. Perfectly dried ingredients can be ground into powder and used similarly to spices. An ordinary kitchen blender can turn freeze-dried fruit or vegetables into a powder so fine that it rises in the air when the blender is opened.
You'll find an advantage when making banana milk, but even a four-legged pet that finds larger pieces of carrot difficult to digest (or doesn't want to eat it at all) will appreciate the ground carrots, although they are very beneficial.