Posted on 08/24/2015 10:24:20 AM PDT by grumpygresh
Is anyone freeze drying food? Have you rigged up your own system, using dry ice, keeping food in the freezer for a couple weeks? What foods are you using? Has anyone bought an off the shelf food freeze dryer?
http://harvestright.com/home-freeze-dryer-machine/
Some of my freezer food occasionally get freezer burned. Does that count?
We have vacuum-sealed our chickens prior to freezing...that’s as close as we’ve come.
DO NOT rely on frozen foods for emergency long term storage.
Dried meats well sealed in containers WITHIN A HIDDEN WALL (or two)
We don’t. We raise and harvest enough chickens to get us through the year. If the SHTF we’ll pull them out, crank up the wood cook stove and start canning.
Freeze-dried food is dried food that does not need refrigeration.
Nope at $3,700+ per unit I doubt I will ever have one.
Didn’t know that there was a freeze dryer model for home use.
I understand food freeze dryer lasts longer, ie: up to 20 yrs, as opposed to < 5 years for heat dried or other methods.
However, the $3800 spent for the home freeze dryer may not have a favorable return on investment.
Wow, that looks really neat! You got me interested, now.
Freeze drying is an excellent way of preserving food. Ever see freeze dried ice cream? They had it back in the 80’s as a novelty of the space program.
It involves putting foods in a cold enviroment (freezer) in a vacuum chamber, and using sublimation at low pressure to remove virtually all of the water from a food product. No water, in a sealed enviroment = no spoilage.
I’ll have to look up their patent application but I’m a bit skeptical. To properly freeze dry, the item has to be frozen and then put under vacuum at a pressure below the triple point. Typically this is about 0.2 to 0.5 mmHg. The frozen water will sublime (solid to gas without a liquid phase) over a period of a day or several days.
The big issue is that the water load is huge. This requires a condenser at about -40 to -60 deg C between the chamber and the pump. This condenser does most of the work. For very small batches dry ice can be used but large scale systems use mechanical refrigerators.
Adsorbents like silica gel or molecular sieve can also be used. But they are high maintenance and only really good for small batches.
I’ve freeze dried some vegetables just to try it. It’s energy intensive in small batches. (1/2 HP pump for a day for some banana slices.)
Again, unless they have some great new system, Mountain House #10 cans are a great deal.
I saw a few vids and articles where they kept sliced apples on a perforated tray in the freezer for 1-2 weeks. If the apple slice didn’t turn black after taking them out of the freezer (for a couple of hours), they were freeze dried and then you could store them in a Mylar bag like any other dry food.
From what I have read on Amazon, the units are noisy, take 24 hours to freeze-dry only a few pounds of food, often with the need to pause to remove ice from the unit by the ice tray.
So it would take you a year of running that machine 24/7 to save up enough food for just a few people. And if TS does HTF, the machine isn’t running anymore, whereas canning jars and a wood stove and pressure cooker will last you for many years.
Freeze dried ice cream is a strange experience. The texture is like a hard, crispy macaroon - almost a chewable, crispy foam; and it tastes exactly like a slice of Neapolitan ice cream.
I first had it at the Smithsonian Air and Space museum. I’m sure you can still buy it somewhere.
-JT
Is there an advantage to freeze dried foods compared to ‘regular’ dried foods? The freeze drying process seems significantly more expensive.
Me too. I knew someone who made it at home, I don’t know how they did it.
We’ve been looking into these things, but so far only have experience with drying in a dehydrator. Apparently, freeze dried foods can last a lot longer; and it’s probably superior for things like fruit and meat.
However, it is extremely expensive, both time wise and in terms of money.
Our experience with drying things like apple slices and especially carrots (we’re currently trying zucchini for the first time) has been excellent. We buy the fruit or vegetables on sale, dry it, and pack it variously, depending on how long we’re hoping to store - some with oxygen absorbers, some just vacuum packed. My husband has also made excellent jerky.
One of the dehydrator companies has a shelf-life chart for dried foods here:
http://www.excaliburdehydrator.com/blog/how-to-extend-the-life-of-your-food/
-JT
That dehydrator looks like a more economical option. What size do you have and how much can you make per day? With harvest season right around the corner, it makes sense to stock up on fruits and vegetables.
We have the 9-tray Excalibur. They make a higher-end one, but this has worked well for us:
My father-in-law had good results with one of the round ones, may have been a Nesco; but we read somewhere that the air-flow in the square ones was better, so we went with the Excalibur. Last night we did about 6 medium sized zucchinis, in 1/4 inch slices; they took up only a tiny bit more than one tray.
There are some good books available on food drying.
Some things shrink amazingly - a few weeks ago there was a sale on celery, so I dried two huge bunches. They dried down to a scant 3/4 cup, and my husband vacuum-packed it into a jelly jar with the Food Saver jar attachment. You could use oxygen absorbers as well.
You may want to get a mandoline, or some other tool to make the chopping/slicing go faster; but in general it’s not too time consuming, and it’s fun. We generally just let it run while we’re sleeping.
(Not associated with Excalibur; it’s just the only one I have experience with.)
-JT
I priced this gizmo awhile back, and really, really want one.
If I had $3000 in the stock market, I’d take it out and buy this machine.
But I don’t, so I’m making do with my pressure canner and my $40 dehydrator for now.
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