Rotovape questions

Capna system with ethanol extraction.

We are currently running our 20l rotovap at 130.09 deg F, 100rpm fully depressurized.

We have decent flow and return of the ethanol, I’m wondering if we are burning off terps unnecessarily. It seems the crude is darker than I expected.

Is there a chart that would explain what I should be operating the rotovape to maximize the complete structure of our product? I turned it down to 80 degrees F and still had evaporation occurring.

Sorry for bland questions, new to the process, any assistance is welcomed and much appreciated.

I’d start by asking what are you extracting, how much tea/ethanol do you need to recover a day and what is your end product goal?

For me, I’m on the hemp side and for the most part our terps are nearly worthless, so we tend to run higher temps for the solvent recovery, and when we decarb in roto we do so at an even higher temp which is guaranteed to cook off and change the terps in the crude.

There’s a lot of complicated chemical interactions between all the ingredients in your crude and the relative portions of those chemicals change with what strain you’re extracting, how potent it is and a host of other factors. So I very much doubt you’ll find a chart that can fully take account of all those different variables.

That said, there’s plenty of people on here sharing their knowledge and SOPs, I think you’ll be better off working backwards from what you’re trying to produce (and how much a day you need to extract or turn out in order to meet your goals).

130f is like 54C that seems wayyyy to hot, my 20L runs at like 30C, and my recovery rates are fine. what kind of vacc pump are you running???

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We run our 50L’s at 42c @ 70-80% vacuum

your vac level’s come into play here

General rule of thumb is
smaller roto = higher vacuum efficiency
higher vacuum = less heat needed to evaporate solvent
less heat = lighter extracts


130 is too hot man. ethanol can evaporate at RT. And you are pulling vacuum as well, so small amount of heat can let ethanol escape. Yes there is a chart you can refer.
use this one, replace the water with ethanol


30-35c should do the trick. If your oil is dark you either have shitty weed or you did something wrong. By answering the following questions we will have the info needed to help identify where you can improve your process to try and get better results. What are you doing for filtration? What’s the quality of your source material (how fresh is it?, how dry is it?, what’s it’s starting potency?, grind or no grind? And how fine if you do), from extraction to through filtration what’s your total solvent contact time? What’s your average extraction temp and soak times? Does the temp hold throughout each extraction or do you see an increase in temp as you extract?

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I use my 50 L for the main evap then transfer to a smaller roto bc it’s easier to get the material out once it’s more viscous .

Do you have any practical tips on how to get the material out of the 50 L flask once the etoh has been removed . My arm doesn’t fit in the 50 L to scrape the flask .