Dehydrated vs Freeze dried

[goofball]

Is it just me or does it seem a bit odd to have food that requires one to add water to. I have seen these long term food storage products and wonder if they are a good idea. I am still in the early stages of my storing but am at the point I need to start collecting stuff that will last long term.

Has anyone had any experience with these products. Would you recommend them or do you have other ideas that work better.

[BenRaines]

We use both freeze dried and dehydrated food products. What is important is to store enough water to mix the foods. It would be difficult to store all products in current state where they will be needed versus dehydrated or freeze dried.

Perhaps a combination of both.

Ben Raines

[Iggy]

Dehydrated - if done at home and done properly and then stored properly will last much longer than canned or frozen.

Freeze dried will last even longer. Plus they take less room to store.

It is easy to use dehydrated foods on a daily basis. I toss some extra peas, carrots, potatoes, onions, red bell peppers and mushrooms into a can of ready to eat soup. Just a teaspoon of each, let it sit for about 1/2 hour in just enough boiling hot water to barely cover, then heat and eat. The soup is heartier and more flavorful with the additions. I buy the store brand of soup as it is the cheapest, then add to it. The soup I get has a lot of extra liquid- I drain some off into a measuring cup, nuke it to boiling, add the dehydrated veggies and let them soak till they are mostly reconstituted.

I also add dehydrated veggies to chicken noodle soup. Makes it even better in my opinion! You can quite often buy a case of chicken noodle soup on sale- there is more than enough liquid per can to reconstitute your veggies.

To dehydrate veggies- buy the frozen veggies when they are on a real good sale. Quickly thaw by putting them in a colander, and running cold tap water on them. Drain and pat dry if they are wet. One bag (16 oz.) should fit per tray of your dehydrator. Once they are dehydrated, package up in an air tight container or vacuum seal in a seal-a-meal. I do 1/4 tray per package.

All frozen veggies are already blanched - just quick thaw them in running water, drain and pat dry.

Some grocery stores sell the not so fresh mushrooms, green/yellow/red bell peppers, etc. at a reduced price. Buy them up, slice/dice and dehydrate! They don't need to be blanched. Do it right away before the veggies mature too much!

Same with onions. Chop or dice them up and then cut some netting (from the fabric store) to fit the trays, then set your dehydrator up in the garage. DO NOT DO IT IN THE HOUSE - the fumes could kill you, your small children or pets. It killed the mice in the walls of my shed!!! Nearly killed me when I did it in the house.

[crytsprospect]

I have a dehydrator... I dry meat and fruit it is really nice but freeze dried stores well . You have to see what your family will eat , try items because having alot of food storage no one wants to eat isn't a good thing either.

[Guest Username-Removed]

Both are excellent for your longer term storage. However, Freeze Dried or dehydrated foods are not recommended by me for 72 hour kits. You simply cannot pack enough water or filter enough water to make this a viable option for a 72 hour or a survival kit. MRE, Ration bars or even canned food is a better option for 72 hour kits ... IMHEO

[crytsprospect]

Word knows :} you are so right about 72 hr kits. The rule about 72 hr kits is keep it simple. My son brings MRE's home from drill some are so very good. They are dehydrated or freeze dried but have a cool water heating system.... the whole thing is awesome.

[KuriChan]

I am fairly knowledgeable in this particular subject because I have been selling freeze-dried food (mostly to LDS families) for over a year and a half now. Freeze-dried is much better than dehydration because the dehydration process involves removing most of the water from the food through extreme heat (causing a grape to become a raisin) which changes the flavor and cooks out several vitamins etc. Freeze-drying is a special process that simply takes out the water and oxygen (leaving everything intact) and lasts much longer.

[goofball]

Thanks for the info. I have found it very useful. I am one of those building up the supply slowly but surely.

I have not heard of cool water heating system. What does that do for the food.

[bcguy]

What exactly is freeze dried?

[KuriChan]

It is a special process that, instead of cooking out all the moisture like in dehydration, you actually pour liquid nitrogen into the food you make which takes out the water and oxygen. Because all the water and oxygen is out, obviously nothing can grow, decompose, etc inside. Since nitrogen is about 70% of our atmosphere, you know it is completely harmless. None of the nutrients, taste, or anything is affected by the process. All you do is add water and its like it never happened... proven up to 40 years so far with the special style we do.

[bcguy]

Well this sounds like the ultimate survival food in a world that could vurn upside down.

I did a search on ebay that came up with several freeze dried units and thay are not cheap. no discussion that thay use liquid nitrogen. Seems thay use a vacume and put the food or what ever in a deep mechanical freeze.

Now only if I got a big abundance of perishable food would it be good to have one of these units.

[Iggy]

Go to Wikipedia and search Freeze Drying. Freeze drying - Wikipedia, the free encyclopedia

[hankpac]

This is my first post here. I am a member of the Church living in Oregon.

The main differences between Freeze Dried and Dehydrated (and MRE):

Freeze dried as explained above, is made by completely cooking a food product, then placing it in a nitrogen atmosphere, to both freeze and dry the product to really cold temps, not attainable by ordinary methods, then the product (which is already bagged) is vacuumed, to near-space values, to remove all air from the bag, and sealed. Shelf life of a freeze dried product in a # 10 can is up to 20 years. In a vacuum bag, about 10 years, and in a non-evacuated bag about 5 years.

Dehydrated foods are dried using heat. There is some moisture, and some loss of food value in the process, and tey do not last as long at freeze dried by several orders of magnitude.

MRE's are completely cooked product, that are then sealed in a "Retort Pouch" the temps are taken pretty high, and are similar to canning. MRE's can last up to 5 years if kept quite cool, but a few days at 100% and you have only months to use them, maybe less.

http://longlifefood.com/images/mre_storage_chart.gif

Dehydrated foods are hard and need to be moistened to eat, but even freeze dried foods can be eaten right out of the bag. A little crunchy, but I have done it. The ice cream is great that way.

MRE's can be eaten cold.

Freeze Drying is not a process you can do at home.

Check out Oregon House Freeze Dried foods, for lots of info on how they do their products.

BTW, Dried, Dehydrated, Freeze Dried, MRE (cooked, and retort packaged), and canned whole are all complementary, and should ALL be a part of a complete home storage package.

Edited June 12, 2008 by hankpac

[sugarcrane2]

I found this when I googled Freeze dry at home. Has any one tried doing it?

You probably don't have a good vacuum chamber at home, but you almost certainly have a refrigerator. If you don't mind waiting a week you can experiment with freeze drying at home using your freezer.

For this experiment you will need a tray, preferably one that is perforated. If you have something like a cake-cooling rack or a metal mesh tray that is perfect. You can use a cookie sheet or a plate if that is all that you have, but the experiment will take longer.

Now you will need something to freeze dry. Three good candidates are apples, potatoes and carrots (Apples have the advantage that they taste OK in their freeze-dried state). With a knife, cut your apple, potato and/or carrot as thin as you can (try all three if you have them...). Paper thin if you can do it. The thinner you cut, the less time the experiment will take. Then arrange your slices on your rack or tray and put them in the freezer. You want to do this fairly quickly, or your potato and/or apple slices will discolor.

In half an hour look in on your experiment. The slices should be frozen solid.

Over the next week look in on your slices. What will happen is that the water in the slices will sublimate away. That is the water in the slices will convert straight from solid water to water vapor, never going through the liquid state (this is the same thing that mothballs do, going straight from a solid to a gaseous state - mothballs are the only thing in a normal person's life that sublimate naturally). After a week or so (depending on how cold your freezer is and how thick the slices are) your slices will be completely dry. To test apple or potato slices for complete drying, take one slice out and let it thaw. It will turn black almost immediately if it is not completely dry.

When all of the slices are completely dry, what you have is freeze-dried apples, potatoes and carrots. You can "reconstitute" them by putting the slices in a cup or bowl and adding a little boiling water (or add cold water and microwave.) Apples you can eat in their dried state, or you can reconstitute. What you will notice is that the reconstituted vegetables look and taste pretty much like the original! That is why freeze drying is a popular preservation technique.

Here's the link: Freeze Drying At Home

[Hemidakota]

This is my first post here. I am a member of the Church living in Oregon.

The main differences between Freeze Dried and Dehydrated (and MRE):

Freeze dried as explained above, is made by completely cooking a food product, then placing it in a nitrogen atmosphere, to both freeze and dry the product to really cold temps, not attainable by ordinary methods, then the product (which is already bagged) is vacuumed, to near-space values, to remove all air from the bag, and sealed. Shelf life of a freeze dried product in a # 10 can is up to 20 years. In a vacuum bag, about 10 years, and in a non-evacuated bag about 5 years.

Dehydrated foods are dried using heat. There is some moisture, and some loss of food value in the process, and tey do not last as long at freeze dried by several orders of magnitude.

MRE's are completely cooked product, that are then sealed in a "Retort Pouch" the temps are taken pretty high, and are similar to canning. MRE's can last up to 5 years if kept quite cool, but a few days at 100% and you have only months to use them, maybe less.

http://longlifefood.com/images/mre_storage_chart.gif

Dehydrated foods are hard and need to be moistened to eat, but even freeze dried foods can be eaten right out of the bag. A little crunchy, but I have done it. The ice cream is great that way.

MRE's can be eaten cold.

Freeze Drying is not a process you can do at home.

Check out Oregon House Freeze Dried foods, for lots of info on how they do their products.

BTW, Dried, Dehydrated, Freeze Dried, MRE (cooked, and retort packaged), and canned whole are all complementary, and should ALL be a part of a complete home storage package.

Have eaten plenty of' MRE's in my days, I detest this product fully but the upside is shelf life.

[hankpac]

What Sugarcane is describing is freezer burn, not freeze drying. Part of a true freeze dry is pulling a hard vacuum. This is what causes the frozen water to sublimate. this article is really poor method as described.

Cryto: MRE's are NOT freeze dried OR dehydrated. they are cooked, and placed in a hermetically sealed "retort pouch". A retort pouch is a plastic bag that allows heating in the pouch by boiling or microwave. The food is fully cooked in the pouch so can be eaten cold.

Goof: "Cool" water meant: Neat, keen, sharp, Out of sight, remarkable, outstanding.

It is a heater that you put water into, and it reacts by creating heat. Slip the retort pouch inside, and it gets your food hot, without flame.

For full info on freeze drying, go to "www.ofd.com" which is the home page of Oregon Freeze Dry, the makers of mountain house.

BTW, Nitrogen is not part of the freezing or drying process. NTG is flushed into a can before sealing to make sure to displace any oxygen. This stops oxidation, and prevents hatching of weevils or other insects, and retards aerobic bacteria action. It is an inert gas.

The person who started this thread may by now realize that having water in addition to food is not in fact unusual. It is a requirement, no matter WHAT kind of foods you store. Even fully hydrated whole foods will require a storage of water for personal hydration usage. That is what makes a thoroughly rounded out emergency and long term storage plan.

Edited July 2, 2008 by hankpac

[kemct]

Hi thanks for the great info I found here.

There is a few comments I would like to add wrt to freeze drying based on research I have done for some of my blog posts.

Critical to the freeze drying process

1) Food is "flash frozen" below -40 degrees F in a vacuum, this prevents food's cell walls from breaking and destroying the texture (and shrinkage) and substantially degrading the nutritional value of the food, as happens when we freeze things at home.

2) Sublimation or removing the water from the food by directly turning from ice to vapor by carefully and gently heating it (typically a maximum of 100 to 130 degrees F) is critical to the process

3) After 98% of the water is removed stopping all bacterial growth, the food is packed, and this is where nitrogen comes in, it is nitrogen flushed so no oxygen is present in the food while it is packed. This is what allows the food to be preserved for so long after the process. If it is vacuum packed in a pouch small amounts of air will seep in over time so the shelf life is typically 5-7 years. If the food is "nitrogen packed" in #10 cans then there will be no vacuum the outside air wants to invade into, so the food can last a lot longer.

So I wouldn't try freeze drying at home and expect the same shelf life.

Mountain House is the commercial brand for Oregon Freeze Dry and they claim shelf life 25-30 years in #10 cans.

I question this number though, while the food may be safe for 25-30 years, will it have the nutritional value and edible qualities then? Other freeze dried food sellers state is the max shelf life of #10 cans is 10-15 years.

This is important because you may want to slowly consume and replace your food reserve at some point over a few years and you want it to be more than just edible then. I am doing some more investigation in this area.

A few other comments;

- Fresh and cooked foods can be freeze dried, it does not have to be cooked.

- Nutritional value degrades once food is harvested, it would be good to know how long typically it takes from the time food is harvested till it is freeze dried. I am investigating that as well. Dehydrating food also destroys vitamins and nutrients. Normal freezing of food is the worst.

- As hankpac mentioned storing water is required regardless. It takes more water to process and cook such as wheat and other staples, as well as soaking dehydrated food than it does to just re-hydrate freeze dried food.

I agree with Hemidakota that a variety of food reserves should be kept.

MRE is excellent if you need to travel or are to use when you are not in a condition to prepare food. But I would not plan 3 months worth of MRE, even the military does not recommend eating their MRE for extended periods. MRE is also the most expensive.

[bcguy]

Where can one buy freeze drying equipment?

[hankpac]

You have had two (at least) posts above explain in some detail that freeze drying at home is impractical.

You are talking equipment that costs thousands of dollars, as well as resources like bulk nitrogen, compressed storage, moving atmospheres under pressure from tank to chamber, evacuating large chambers to hundreds of pounds of vacuum.

It takes a large industrial setting.

Still wanna buy the equipment?

Go to Oregon Freeze dried foods, and talk to them. I am sure you will get all the info you need.

Oregon Freeze Dry, Inc. Lyophilization, freeze dryer, toll dryer, freeze drying, toll drying, freeze dried, Lyophilization Processor/Manufacture of freeze dried materials, such as pharmaceutical chemicals, medical devices, sensitive biological's, and