10 Differences Between Freeze Dried And Dehydrated Food. What Is The Best One?
Freeze drying and dehydration are two popular ways of boosting the shelf life of food for future consumption. However, with the ongoing hyped up craze about dehydrating machines and all their benefits, it’s understandable if you are lost between storing your foods by freezing or switching to a food dehydrator.
While these two processes serve the same purpose- adding life to the food in season for consumption when that particular food is out of season- each has its own benefits and drawbacks.
Needless to mention, it pays to understand how the two methods vary before committing to one. Let’s help you here.
So, What Are The Differences Between These Two?
To understand the major benefits and drawbacks of each of these models, it pays to have knowledge of the processes involved in both and how each of them works first.
Freeze drying is a 3-step process. It involves selecting the type of food that you want to dry and freezing it. Next, the food is placed in a strong vacuum. Here, the ice crystals in the food sublimate turn directly into water vapor rather than passing through the liquid state.
The food is then placed in vacuum storage bags or containers and stored either in a freezer, pantry or in an emergency kit when prepping.
On the other hand, dehydration involves using heat, dry air, and air movement to remove water from food. Dehydration can be done with or without a dehydrator (read more about dehydrating food without a dehydrator).
Of course, the first consideration that should top your checklist is how good each of these methods preserves the nutrients in your food.
Freeze-drying has the upper hand at this front. Researchers suggest that since freeze-drying food involves removing up to 98% of the food’s water without the use of heat, the food tends to maintain a significantly higher nutrient content compared to dehydration.
A 2011 study published in the journal for National Institutes of Health wanted to investigate the effects of freeze-drying on the antioxidant compounds in selected fruits.
At the end of the study, the researchers reported that this method didn’t exert significant changes in the number of nutrients.
On the other hand, dehydration is known for leading to a higher loss of nutrients. This could be attributed to the fact that this process involves subjecting the nutrients to high heat (up to 140℉) and light.
For instance, some vitamins such as A and C tend to decrease once they are subjected to high heat or even air. The A vitamins are also sensitive to light. Therefore, the sun will definitely have a toll on them if you are relying on it to dry your food.
Having seen that some vitamins and minerals are stripped when dehydrating than during freeze-drying, it’s pretty much obvious that freeze-dried food tastes great.
Freeze-drying removes water only. Since it does not involve heating, the nutrients, flavors, and color of the food are left intact and remain so for quite a long time with proper storage.
Worth noting, this is what makes most nutritionist and food experts to recommend freeze-drying when dealing with herbs.
4. Use Of Additives
Another major difference between these preservation methods is the use of additives. If you are fond of buying dehydrated food from stores, then you must have realized that they have very high sugar contents. This sugary taste comes from the preservatives added during storage to extend the food’s shelf life.
On the contrary, freeze-dried food has almost 98% of its water content removed. This translates to a reduced foothold for bacteria that make food go bad. This also means that fewer (if any) additives are used.
Be advised, however, that the only way to keep off additives and preservatives from your stored food is to freeze-dry or dehydrate it at home.
This is where dehydrated foods beat their freeze-dried alternatives. As I have told you before, freeze-dried food has most of its water content removed. Dehydrated food, however, has a considerable amount of its water content sealed in.
As a result, dehydrated foods have a chewy texture and are sweet in taste. Unfortunately, remember that their taste slightly differs from that of fresh food due to the sugar, salt, and other preservatives used.
On the other hand, freeze-dried food tends to have a crispier and crunchy texture since they are virtually dry.
People are coming up with ways to freeze dry or dehydrate different types of food each day. However, it’s undeniable that freeze-drying offers a lot of options than any other food preservation method.
Freeze-drying allows you to use almost all foods ranging from high-water content to low-water content varieties. This means that you can freeze-dry not only herbs but yogurt, ice cream, cheese and fruits among others.
On the other hand, dehydration mostly favors low-water content foods. This limits you to certain meats, vegetables, and fruits such as apples (see 20 best apples to dehydrate here).
Regardless of the method that you go for, you’ll want to rehydrate your food before consuming it. Freeze-dried foods are much easier to rehydrate than dehydrated foods. The best part about rehydrated freeze-dried food is that it’s almost similar to fresh food in all aspects. These foods also rehydrate easily and only require water (hot or cold).
Dehydrated foods are another story. These foods can be really tough and this means that rehydration won’t be a walk in the park.
While cold water can still be used to rehydrate dehydrated foods, hot water is most preferred since it speeds up the process. Beef jerky, for instance, takes up to 4 hours to rehydrate when using cold water. On the other hand, the same process could be done in utmost 30 minutes using hot water (see how to rehydrate jerky).
While the use of hot water seems more promising, it might be a huge problem during emergencies and when you are far from civilization.
8. Cooking And Baking
Basically, both freeze-dried and dehydrated foods can be rehydrated and be used in a variety of dishes. All in all, freeze-dried food offer more options in that, they don’t vary much from fresh foods upon rehydration.
Dehydrated foods, on the other hand, remain very different from fresh their fresh food derivatives. This means that the two don’t deliver the same results. You could be limited to certain dishes due to this reason.
9. Shelf Life
Freeze-dried foods still take the lead here. Dehydrated foods contain between 30-50% of their water content compared to the 2% water content in freeze-dried foods.
What this means is that while these two methods aim at extending your food’s shelf-life, dehydrated foods are more susceptible to microbial growth than freeze-dried foods.
That being said, you should expect the latter to last for much longer. In fact, experts say that freeze-dried foods could be stored indefinitely if is stored in a free-standing freezer at zero degrees Fahrenheit.
This is subjective though. Whether you are dealing with dehydrated or freeze-dried foods, minute leaks in the packaging bags, cans, or jars could lead to bacterial growth even without causing any color changes on the package. Therefore, proper care is required irrespective of the method of preservation that you go with.
10. Cost And Efficiency
Freeze-drying your food seems like the best way of preserving food until you consider the cost. This method is usually quite costly especially in terms of power. Store-bought freeze-dried foods are also considerably costlier than their dehydrated alternatives.
In addition, these units don’t require so much power to run. Thus, you could save hundreds by dehydrating lots of food for usage when the supply is low.
On the same note, as another article on this site shows, you don’t need to rely on a food dehydrator to dry your food. There are a lot of other ways to do this including spreading it in the sun, putting near and atop a fire, or even hanging it in your car!
Worth mentioning, however, is that dehydration can be time-consuming. This depends on the method of dehydration that you are using and the size of your family.
All in all, considering most of the other factors, freeze-drying stands out in terms of efficiency and speed. The key benefit here is that there is less waste credit to the long shelf-life of the foods. In addition, most freeze-dried foods can be added to virtually any dish that requires freshness.
Freeze-drying and dehydrating food are great ways of prolonging your food’s shelf-life and saving on cost in the long run.
However, either of these two methods has its pros and cons.
At the end of the day, what matters is your preference, the types of foods that you’ll be dealing with the most, and what you intend to do with that food.
If you intend to store food for a couple of weeks or months, dehydration might work for you. On the other hand, if you want to store lots of food for years and don’t mind power consumption, you might consider freeze-drying.