I’ve been hooked on freeze-drying for a while now. I’ll give you a fair warning: I haven’t actually purchased a freeze dryer yet. The more I research these machines, the more I am convinced a home freeze dryer, used in conjunction with a vacuum sealer, is the ultimate prepper setup. I see it as an excellent combination for preserving foods and meals I usually freeze into shelf-stable lightweight sustenance.
Freeze drying food is better than dehydrating food because freeze-dried food can be rehydrated and used as if it were frozen. Freeze-dried food is also superior for creating food powders for flavoring, stocks, soups, and dehydrated meals.
Now, I won’t be replacing my dehydrator. I will keep using it for drying herbs, fruit leathers, and fruit for my homemade trail mix and granola. I do see myself using a freeze dryer to create and package a bunch of ready-made meals like fajitas and chicken soup as well as drying and shelving this year’s green bean harvest.
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Difference Between Freeze Drying and Dehydrating
Freeze drying food is not the same as dehydrating food. Both methods will dry food out, creating a shelf-stable version that can be stored for much longer than fresh, but that is where their similarities end.
To dehydrating food, a device is needed that uses heat, air circulation, or a combination of both to dry out food. It can be a stand-alone appliance with stacks of racks, your oven, or even a big fan. Think of dried herbs found in jars or packets at the grocery store, such as oregano, sage, and thyme. These herbs have all been dehydrated commercially, in a similar way you would use a dehydrator at home.
Popular foods dehydrated at home include jerky, fruit, vegetables, and herbs. There are many online communities centered on the topic of dehydrating that share tips and methods, like the dehydrating sub over at Reddit.
A freeze dryer works in a completely different manner. Like a dehydrator, it removes moisture from food spread out on trays. Unlike a dehydrator, a freeze dryer flash-freezes to temperatures below -30°F and then uses a vacuum process to vaporize and suck moisture out of the air. This process reliably removes far more moisture from food than dehydrators do, and it does it without cooking it.
Some popular foods to freeze-dry include cooked and raw fruits and vegetables, meats, sauces, baked items, and dairy.
Which is Healthier: Freeze Dried or Dehydrated Food?
If the food you are preserving is healthy, then both methods of food preservation are healthy. The term “Garbage in, garbage out” is relevant here. If you are drying junk food or foods high in added sugar and artificial preservatives, we can’t talk about how healthy it is. And yes, you can dry junky foods with both of these preservation methods.
When talking about natural, whole foods, using a freeze dryer is slightly better when comparing nutrition values. Depending on the tools used, the process of dehydrating can involve heat. Heat can destroy or degrade vitamins and minerals. Methods like sun drying or air drying can cause damage to your food. There is a phase where enough water is in the food to allow natural decay processes to take place. Also, some vitamins are destroyed with exposure to light. A tip is to make sure that the time it takes to dehydrate your food is short enough to minimize these processes and stop your food from spoiling.
Freeze drying, on the other hand, has the advantage of using cold temperatures, which is in itself a form of food preservation. Next, a vacuum pump pulls moisture out of the food while it’s in a frozen state. This method leaves behind the majority of nutrients in the food wholly untouched and is considered healthier overall.
Which tastes better?
While personal tastes will have more influence than anything, it will also depend on what you want to store. There are some foods that some would argue the need to be preserved with a dehydrator. Trail mix needs dried fruit, or it isn’t trail mix. Jerky would never get its delightfully chewy texture from a freeze dryer.
Freeze drying is different. Many foods that have been freeze dried can be rehydrated to almost the exact same texture and flavor that they would be if they had only been frozen and thawed. Meats can be freeze-dried raw or cooked and used as you would normally.
I love batch cooking, and I enjoy taking a weekend each month to cook all of my food. The problem is that fridge and freezer space is a premium in my house, especially in the summer, when I’m harvesting or buying bulk produce. The solution to my space problem is to batch cook and then dehydrate and pack meals. Spaghetti sauce, mashed potatoes, soups, fully cooked and sliced roasts, and even breakfast scrambles are all quickly dried and stored in the pantry, ready to go at a moment’s notice.
The following video shows how an organic tomato that’s been freeze-dried rehydrates.
Some foods even turn into yummy, healthy, crunchy snacks with no rehydration needed.
Do Freeze-Dried Foods Last Longer Than Dehydrated Foods?
Foods that have been properly freeze-dried have no real-world advantage over dehydrated foods. Both have a long shelf-life. Making sure the preserved food is stored correctly is really the determining factor. Vacuum sealing or keeping food in an air-tight container is the best way to help your food stay dry and safe. The addition of a desiccant or oxygen absorber, when acceptable, will keep the quality and flavor even longer.
Though it is thought that freeze-dried food will last longer than dehydrated food because it contains less water, that confidence only goes so far. Freeze-dried food will readily soak up a little more moisture from the air it’s exposed to because it’s that much drier to start. This is why freeze-dried foods aren’t considered to have much of an advantage.
Which is Cheaper?
The up-front costs of freeze-drying are far more than dehydrating. Home freeze drying is still a relatively new concept, and home freeze driers are very expensive.
Dehydrating food at home can be done with no extra equipment. Plans for solar dryers are found in popular homesteading forums. Some people use their oven. I personally find a home dehydrator to be well worth its investment. Dehydrators don’t have to be fancy at all and start at around $40. Some balk at yet another kitchen gadget, but my dehydrator is used nearly 8 months out of the year. Mine sits on my countertop from late spring to mid-fall, happily whirring away as it dries. When my harvesting is done for the season, it lives on a shelf in the basement.
My personal experience with dehydrators has been a cheap one. A simple dehydrator I bought nearly a decade ago is on sale from time to time for less than $30. It has a temperature dial, screens, fruit leather trays, and regular trays that suits my needs just fine. I won’t upgrade until I’m convinced I need a larger dehydrator. My oven works well as a secondary dehydrator when I need extra room, and at this time I only dehydrate fruit I buy in season. I do lots of jerky batches every year, but I do that in my smoker.
Home freeze dryers are a big investment upfront. Home freeze dryers are still pretty rare, and entry models are above $2000. Models with larger capacity and upgraded vacuum pumps can cost much more. Freeze drying at home is an investment, and I would not suggest investing in one unless you are a proven prepper.
I feel that a home freeze dryer will pay for itself if it’s used regularly as part of a food preservation and storage plan. The sheer volume of things you can freeze dry is so much greater than a dehydrator. If you would freeze it, you can freeze dry it. Harvested produce from your garden freeze-dries brilliantly. You can freeze-dry your produce before it turns, and in turn, you can grow more.
All in all, both methods can be considered worthwhile to those who live a self-sufficient and frugal lifestyle.