Why do rotavaps suck? And what should we do?



I’ve got a couple smaller rotavaps, and I can’t help but notice they’re not very efficient for the price, nor are they very good at removing more than 80% of solvent in an oil.

I’m assuming I’m not running it wrong…but Everytime I take my oleo from the roto into the short path, I find at least 30%+ coming back in solvent. It’s annoying in quite a variety of circumstances.

Does anyone have any tips for better & convenient solvent removal? The short path seems like my best option at this point. Anyone else feel me?


What kind of temps are you setting your roto water bath to?

I’ve found I need to kick it up to at least 80c to get most of the ethanol out.


Ew, yeah i only fire it up to 55c usually to try and keep some turps intact.

I had thought about some kind of sloped hot plate and spray nozzle setup in a vacuum chamber


If you are putting it into the short path, why would you be keeping terps? That’s just a bigger fart fraction to deal with.

Definitely give turning up the temp towards the end a whirl.



If your rotovap disappoints and you want to use the short path for recovery of alcohol you won’t be able to live with it . Lol. Option 1 try deeper vac and your collection vessel empty. Option 2 is decarb while in roto and that should remove everything . But then it helps when there’s a bit of alcohol left to transfer into spd or removing from roto flask In general