I have to do an experiment which involves getting the extract of certain leaves. I had decided to macerate it in ethanol (70%) solution and then to evaporate the solvent using water bath/rotary evaporator.

Due to the pandemic, I couldn't get access to labs to conduct this experiment. Is there any other way to evaporate the solvent at home without the need for water bath/rotary evaporator?

This extract will be used for testing antibacterial effects. So, I'm kinda concerned about simply heating up the solution because it may destroy the necessary compounds. Would it work if I try to heat the solution in lower temperatures?

Thank you,

  • $\begingroup$ I would use a combination of vacuum and water bath. $\endgroup$
    – Andreas
    Commented Mar 23, 2021 at 11:36
  • $\begingroup$ How much liquid are we talking about? Ethanol will just evaporate when leaving it open, so you could just leave it open outside somewhere so your flat is not covered in ethanol fumes. $\endgroup$
    – Inselino
    Commented Apr 22, 2021 at 9:12

2 Answers 2


Free evaporation or using a water bath ?

Both ethanol and water evaporate at any temperature, just with the exponential-like rate. ( Washed clothes will dry up even at freezing temperatures ).

If living in area with currently cold weather, consider using evaporation on the central heating radiator, parhaps partially isolated.

Free evaporation could be a safe bet, but slow evaporation can support oxidation of dissolved substances, so I would try both free and heated ways.

I remember that in my young-chemist days, I had bought a water stream vacuum pump, based on the Bernoulli equation.


Setting up a fan blowing over the top of whatever you are storing your extract in would be more than enough to evaporate any sort of alcohol/water mixture. It might take a while, but unless you have another option then it could be worth trying.


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