DIY Freeze Dryer

[BigCedarJack]

Has anyone built their own freeze dryer? Have any tips?

 

[WoodBow]

I have not but i have sure thought about it. Seems like all you need is a sealed chamber you can chill with dry ice and then add a vacuum pump.

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[Dos Perros]

I saw someone selling on Facebook marketplace a stainless steel vacuum chamber, a little smaller than a 5 gallon bucket. I thought about building a DIY freeze drier.

But, dehydrating is mostly superior, IMO, and I already do that now.

 

[Nickofthewoods]

Following along. Given how ridiculously expensive freeze driers are it would be cool to see someones homemade version.

 

[BigCedarJack]

I've been researching it a lot. I'm currently trying to source the vacuum pump. I might try one from the dentist office.

 

[tdot]

If the Dentist pumps dont work out, you could check out vac pumps used either for veneer presses or vacuum clamping systems (both in the woodworking world) there are a number of options and not expensive.

Not 100% sure how vac freezing works, so this may be a useless idea. Vac chambers are often an issue. Could you put the food in a vac bag, and the dry ice outside it?

 

[WoodBow]

If the Dentist pumps dont work out, you could check out vac pumps used either for veneer presses or vacuum clamping systems (both in the woodworking world) there are a number of options and not expensive.

Not 100% sure how vac freezing works, so this may be a useless idea. Vac chambers are often an issue. Could you put the food in a vac bag, and the dry ice outside it?

Under enough vacuum and below a certain temp, water bypasses the solid state and goes straight from a liquid to a gas and is pulled out. I do not believe a vac bag would work. I assume you need some free space.

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[tdot]

Under enough vacuum and below a certain temp, water bypasses the solid state and goes straight from a liquid to a gas and is pulled out. I do not believe a vac bag would work. I assume you need some free space.

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Cool, thanks.

There is something called a Breather Cloth that is used to help extract air and liquid (glue, water, epoxy, etc.) from wet laminations that have been put in Vac Bags.... might be a solution.

Here's a pump that I have, been using it for years as a vacuum press

Rebuilt Thomas 3.15 CFM Vacuum Pump - $138.00 each

Check out our collection of more than 4,500 exotic and domestic wood veneers. See pictures of every veneer in stock including more than 200 walnut burl veneers.

www.veneersupplies.com

 

[Wrench]

How many inches of vac has to be maintained? I too have wanted to give it a try.

 

[PhlyanPan]

I've wanted to do this too. I always planned to use an HVAC vacuum pump.

 

[mlsthmpsn]

For anyone looking for pumps, you need to pull a minimum vacuum pressure of 4.58 mm Hg and get the temp below 0° C.

If you can locate one, a small 1/10 to 1/4hp rotary vane compressor would pull that easily, and they are designed to run continuously as this application requires.

 

[Leroy91]

It is pretty easy and light to dehydrate home cooked meals spread out on parchment paper on a cookie sheet at 200-225F in you oven. Just keep the oven door cracked slightly. Vacuum seal and freeze, then take out and eat those meals first before your store-bought freeze-dried meals. Even in the summer, I am pretty confident to have my DIY dehydrated meals for 2-3 days. If I am going out longer than that, I just bring some Mountain houses for the 4th and 5th days.

 

[Moserkr]

Leroy, do you add oxygen absorbers to your dehydrated meals you make? Do you store the meals in the freezer before you hunt?

 

[Elkslayer67]

I looked into making one. The process takes the water in the food from a solid state ( ice ) to a vapor bypassing the liquid state. While you can do this to a limited amount with dry ice and a vacuum chamber to do larger batches (i.e. meals) you need to maintain both a vacuum and refrigeration for long periods of time while simultaneously warming the food. Causing the water to enter the vapor state which refreezes as ice on the outer walls of the chamber. This application of heat to the food is what makes the process efficient. With this, it still takes a long time to thoroughly freeze dry batches large enough to make it worthwhile( 24 hours or longer). Using the dry ice and chamber vacuum it could take a month to totally freeze dry a meal size batch and it still would probably have moisture in it. Now it is possible to put a heating element into a chamber vacuum and put that into a freezer unit but you would have to monitor it and cycle the heat on and off through the drying process. This is rudimentary and will have questionable results. All that being said it makes the $1999.00 to $ 3499.00 price tag the cheaper option. But that is just my opinion. To be perfectly honest, I have been agonizing over purchasing a unit for years now. Maybe this will be the year?

 

[Leroy91]

Leroy, do you add oxygen absorbers to your dehydrated meals you make? Do you store the meals in the freezer before you hunt?

I do try to keep absorbers from other manufactured meals, but don't worry about it too much.
Yes, I do keep them in the freezer until I am going out to camp.

 

[divingpa]

I looked into making one. The process takes the water in the food from a solid state ( ice ) to a vapor bypassing the liquid state. While you can do this to a limited amount with dry ice and a vacuum chamber to do larger batches (i.e. meals) you need to maintain both a vacuum and refrigeration for long periods of time while simultaneously warming the food. Causing the water to enter the vapor state which refreezes as ice on the outer walls of the chamber. This application of heat to the food is what makes the process efficient. With this, it still takes a long time to thoroughly freeze dry batches large enough to make it worthwhile( 24 hours or longer). Using the dry ice and chamber vacuum it could take a month to totally freeze dry a meal size batch and it still would probably have moisture in it. Now it is possible to put a heating element into a chamber vacuum and put that into a freezer unit but you would have to monitor it and cycle the heat on and off through the drying process. This is rudimentary and will have questionable results. All that being said it makes the $1999.00 to $ 3499.00 price tag the cheaper option. But that is just my opinion. To be perfectly honest, I have been agonizing over purchasing a unit for years now. Maybe this will be the year?

It seems as though you've done your research. Although I love DYI projects, I believe this is one I'll skip and go right to the pro's. Have you done any research on what manufacturer/model you'd purchase for doing personal sized batches?

 

[fmyth]

I've been researching it a lot. I'm currently trying to source the vacuum pump. I might try one from the dentist office.

Here is a used Vac pump for a food freeze dryer: https://phoenix.craigslist.org/evl/for/d/mesa-jb-industries-vacuum-pump-for/7077328974.html listing says its made by:

Freeze Dryer Accessories - For your in-home freeze dryer

Our Flush Kit is the simple solution to changing oil in a Harvest Right Freeze Dryer. The pump is a closed-loop system, making it the easiest way to perform a power flush on your vacuum pump.

www.freezedryeraccessories.com

.

 

[Elkslayer67]

It seems as though you've done your research. Although I love DYI projects, I believe this is one I'll skip and go right to the pro's. Have you done any research on what manufacturer/model you'd purchase for doing personal sized batches?

As far as I have been able to find HARVEST RIGHT is the only manufacturer of freeze driers that would be affordable and sized for home use. The other small units I found are for lab use and priced as such. COASTAL FARM AND GARDEN has the small unit in store. Otherwise it is a direct from manufacture product.
I am planning on purchasing one. Right now I am torn between buying the small unit now ( priced at $1999.00 ) or keep on saving and get the larger unit ( priced at $3499.00 ). Let me know if you get one. And how you got it by the wife

 

[divingpa]

Thanks so much for the specifics. After checking them out I’ll see what my wife thinks. She big into backcountry hiking and camping as well as wholesome home cooked meals. She might want one more than I do