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Can you freeze dry food at home? Answered

I would like to know how to freeze dry food.

Could some create an Instructable How-To,...

Can someone build a machine that freeze dry food?

There are essentially three categories of freeze-dryers: the manifold freeze-dryer, the rotary freeze-dryer and the tray style freeze-dryer. Two components are common to all types of freeze-dryers: a vacuum pump to reduce the ambient gas pressure in a vessel containing the substance to be dried and a condenser to remove the moisture by condensation on a surface cooled to -40 to -80 C (-40 to -112 F). The manifold, rotary and tray type freeze-dryers differ in the method by which the dried substance is interfaced with a condenser. In manifold freeze-dryers a short usually circular tube is used to connect multiple containers with the dried product to a condenser. The rotary and tray freeze-dryers have a single large reservoir for the dried substance.



Thank You

Discussions

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GASSYPOOTS
GASSYPOOTS

8 years ago

reverse engineer a pressure cookers heating elements to be able to freeze foods and change the pumps polarity and test it out

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corradini
corradini

Reply 2 months ago

Oh - sure! you can just reverse the polarity (switch the positive and negative terminals) on a heating element, and it'll turn into a chiller. Dang - why din't I think of that!?!?
(This has the potential to revolutionize the entire - well, EVERYTHING heating-and-cooling related - we're talking trillions of dollars!)
Wait. No.

Jeez, I hope you were kidding - the bit about "changing the pump's polarity" makes me think you might've been, because that's nearly as absurd. So let us laugh, together, you and I.

[To be fair: (a) you can 'reverse' a Peltier thermoelectric element to heat or cool (actually you just need to pick which side to use) - but not any 'normal' heating element, and (b) yes, pumps can in theory also be used 'reversibly' - expansion & compression are 2 sides of things - but 'polarity' ain't what we're talking about there, either. So either your humor is a little too subtle to tell that it was humor - or...well, there's the Be Nice policy and I'm not gonna violate that. :-)]

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acomisp
acomisp

8 years ago

Steveastrouk,

Could you explain more about your pressure cooker idea?

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steveastrouk
steveastrouk

Reply 8 years ago

A pressure cooker makes a fine pressure vessel to contain the vacuum . You'll need to get a compressor out of an old refrigerator to make the pump.

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steveastrouk
steveastrouk

8 years ago

That's a pretty good summary. Some substantial engineering in it though. I suppose you could do it inside a big old pressure cooker.

Steve