Can you make your own freeze dryer...easily?

[keepitlow]

You can buy a small 5 CF chest freezer for $180. It is much bigger than a freeze dryer. Drill a hole in the side and run some vacuum hose in it. (Shop-Vac?)

Any ideas about making a homemade freeze dryer instead of paying $4,000?

[Spanky8601]

Originally Posted by keepitlow

You can buy a small 5 CF chest freezer for $180. It is much bigger than a freeze dryer. Drill a hole in the side and run some vacuum hose in it. (Shop-Vac?)

Any ideas about making a homemade freeze dryer instead of paying $4,000?

The key is having a good vacuum pump to remove all the moisture as you warm the product.

[user120312]

Haven't done it but a small chest freezer and the vac pump I use for HVAC would work. Cost/benefit is another factor. I've done fine laying in a supply of ready to eat shelf stable commercial products. I rotate to keep a six month inventory on hand. Use by dates usually are 1-2 years. However, I'm not really a 'prepper', rather have lived rural for decades.


When I was young, mom smoked and sulfured and canned to preserve.

[Zamble]

Our freeze drier works like this. We load the food. Start the programming. The vac pump evacuates the air and lowers the temp to -15 or so. The heating pads lining the tray mount for each of the pad gradually raises the temp to 125 or higher, depending on you setup. And the cycle repeats until the sensor doesn’t detect any moisture coming from the trays. It runs on the average of 24hrs, depending on what we are freeze drying. Something’s have to be pre-frozen or you have a nightmare of clean up.

[ChuckD]

Disclaimer: I have never owned or used a Freeze drier; I have done a ton of dehydrating and a fair amount of research in to Freeze Driers.

I can, in my $200 dehydrator, dehydrate everything I want to and even on the cheap - adding a freeze drier would not be worth the cost of operating, much less buying. The main difference that I have found is that when I dehydrate raw eggs they are still raw and the powder should be handled like a raw egg where in a freeze drier the conditions kill salmonella and so the raw egg can be used without any concern of salmonella.

There is also a major consideration in the nutrition of the food. I can slowly dehydrate at under 135 degrees and keep many of the enzymes in the food alive, where this is impossible in freeze drying.

Also I like the capacity of my large dehydrator; your idea fixes the capacity issue but most of the Freeze Driers I've seen available are very small.

In short my advice would be that your time & money are better spent on getting into dehydrating and storing the dehydrated food.

Also you'd get a better bang for your buck out of that freezer by using it to enable buying large quantities on sale & freezing.

[Zamble]

So, freeze drying at 125 kills the enzymes? Or is the freezing part?

[ChuckD]

Originally Posted by Zamble

So, freeze drying at 125 kills the enzymes? Or is the freezing part?

My understanding is that it is the degree & rate of change. There is also a lot on wet heat vs dry heat - not sure if that applies to wet freezing as opposed to dry freezing or not?

[luckylogger6]

Freeze drying uses a ton of electricity and in CA ours is some of the most expensive in the country. PGE is .30-.50 per KWH making the Harvest Right unit cost about $10-15 per batch.

I wanted to get one but the cost to run doesn't work in CA. Maybe a larger homemade unit could be made more efficient....

[Zamble]

Fortunately we have cheap energy in North Idaho. Our bill averages $150 during the summer, while keeping the house at 73. By comparison, when we lived in Stockton, keeping our house at 78 in the summer we had $400ish energy bills. It was utterly ridiculous.