Comments on: Rotary Evaporation in the Kitchen

By: Dave A

Dave A — Fri, 04 Dec 2009 14:24:57 +0000

By the way, for anyone reading this thread, I did not mean you should put LN through the tubing on a regular water condenser. Don’t ever do that. I would guess that you’d have a decent chance of blowing up your glassware. I meant to say you could use LN in a cold finger condenser. Our friend Shinderhannes pointed this out as well as reminding me that a dry-ice alcohol or dry-ice acetone mix in the cold finger would be adequate (I don’t have dry ice floating around all the time so it slipped my mind).

By: Stephen

Stephen — Fri, 04 Dec 2009 11:43:29 +0000

Thanks! Makes sense about the solids. Might try mashing. I have a Heidolph 4011.

By: Dave A

Dave A — Fri, 04 Dec 2009 04:01:53 +0000

Hi Stephen,
I’ll try to get a part list together. What type of rotovap do you have? I think the Heidolph and Buchi receiver flasks are interchangeable. I don’t know about Yamato. I have never done solids. MKy guess is the evaporation rates would be fairly slow off of solids. The disadvantage of slow evaporation rates is more flavor loss through the vacuum system. One way around that is to use an LN condenser so that everything is trapped and frozen. Problem with that is you have to break the system down to drain it and you can’t taste as you go.

By: Stephen Quirk

Stephen Quirk — Fri, 04 Dec 2009 01:49:18 +0000

This is the most amazing thing! Thanks for the very detailed post (and recipes). Would it be possible for you to provide a parts list and more information on your peristaltic pump arrangement and how you connect it? That would be very helpful to people like me who are putting a system together. Any more recipes? Have you tried working directly from solids (like a pile of berries)? Thanks for any further info/insight. Awesome innovation in the kitchen.

By: Dave A

Dave A — Tue, 13 Oct 2009 00:58:11 +0000

Dunno. Our freezers run about -20C. -70C might be better.

By: Jered

Jered — Mon, 12 Oct 2009 23:39:40 +0000

How do you store your distillates? Might you have better luck with longevity (e.g. habanero vodka) with a -20C freezer? (I would suggest -70C but those are more of a pain.)

By: Kerry

Kerry — Sun, 11 Oct 2009 12:12:04 +0000

Oh god, now I need a jury rigged rotovap to go along with my jury rigged vacuum microwave. Or maybe I could just add a little alcohol to the item I’m drying and save the stuff in the vacuum container.

By: Dave A

Dave A — Wed, 07 Oct 2009 13:21:40 +0000

Howdy Sygyzy,
Most of the perfume work is done with steam distillation. Steam disrupts the cells in the plants and carries oils and flavors with it that are recondensed in the condenser. It is different from what we do in a rotovap. I haven’t done it myself, but I’ve always been interested in it. Steam distillation is also legal because it doesn’t require ethanol. Most of our work doesn’t taste as good when done with water vs ethanol. There is a good (but 120 years old!) description of steam essential oil extraction in this book: http://books.google.com/books?id=uau5AAAAIAAJ&printsec=frontcover&dq=treatise+distillation+duplais&as_brr=1#v=onepage&q=&f=false.

By: sygyzy

sygyzy — Tue, 06 Oct 2009 23:15:30 +0000

Chef, if I am only interested in extracting flavors, would a perfume distiller be an alternative to a rotovap? Do you know of any turnkey solutions?

By: Dave A

Dave A — Sun, 30 Aug 2009 13:51:19 +0000

Hi Sebastian,
Instead of spinning the distillation flask I’m going to put the product in a closed inclined cylinder and magnetically rotate a polycarbonate cylinder inside of that. We don’t use anything that will eat polycarbonate. Also, I have just started experimenting with replacing the peristaltic pump with a liquid/gas diaphragm pump from KNF Neuberger. So far, so good. We’ll post on it soon.

Thanks for reading