Thursday, June 15, 2006


TGIF. Back to real life, slaying dragons and what-not. AND, most importantly of all, figuring out at what point it becomes economical to buy a lyophilyzer (freeze-dryer) - rather than, say, building a crappy one with parts from eBay.


Jacob said...

There's some good plans on building a vacuum pump here:

From there it would probably be possible to build a little vacuum chamber out of a canning jar or something similar, and use a dry ice bath to do the freezing.

Tim said...

Cool Jacob, thanks! I'd probably buy the pump off eBay, seeing prices from 100-200 dollars, but the rest would be jury-rigged.

As it is, a 4 grand machine to put out maybe a kilo a day at most of raw material (about 100 grams processed) would become economical at around the point where I use between 60 and 100 kilos of processed foodstuffs - and I can see doing that in under a few years. So it might just make sense, but of course, building one has additional benefits and self-satisfaction...

I think the biggest problem is condensing and removing the water vapor, since it may damage the seal of the vacuum pump (from what I've read) - to just freeze it back in the chamber would leave it available for resublimation, very inconvenient.

Jacob said...

If you don't mind me asking, what will you be using this contraption for? Super-jerky? Homemade astronaut ice cream?

If the humidity would be a large problem, you could probably run the gas through a tube of drierite or something similar. I don't know how expensive it is (the website is running sloooow) but it can be regenerated over and over.

Tim said...

Jacob, thanks again! Good ideas, using an extremely hygroscopic mix might just do the trick.

Mostly I want to powder fruit to use as a flavoring ingredient, but I'm also looking to try dehydrating a number of finished pastry and confectionery products (including ice cream, as a start). Come to think of it, even some hard-to-dry at home things like goat's milk would be interesting.

Typically I wouldn't need much per day - no more than a few hundred grams of material, is my best guess, but and surpluses will store well.

And actually, I've been thinking of processing my own instant noodles, so it's a good way to dehydrate noodles without frying in coconut oil.

hereandthere123 said...

Do you absolutely need a freeze dryer or would a regular dryer do?

By the way, thanks for your visit to my site. I'd be happy to do a food trade and mail you Barilla in return for something appropriate from Russia. :D


Tim said...

Hey Deb! Ditto the thanks for posting here :-)

A regular dryer would do for the most part, but a freeze dryer would be invaluable for making easily-remixed powders, as well as some of the confections I'd like to try out. I'm a nutty experimenter, and even though I'm usually reinventing the wheel, the journey is half the fun!

I'll send you an e-mail and we'll talk :-)