Hello, there's been extremely low winter temps overnight in my friends area and he was wondering if it were possible to leave his freeze precip jar outside at night without a lid, letting the naptha evaporate and recrystallization to occur at the same time? Or would this negatively effect the process?

He thanks you in advance.

It will evap a lot slower, but with low temperatures you'd have issues with moisture.

Naphtha, as most organic solvents, will evaporate when open to the atmosphere. This solvent will not evaporate quickly at low temperatures, but best to leave the container covered to preclude moisture or anything else from falling into it. Freeze precip. should work fine with this technique.

Slow evaporation yields some sexy crystals. I highly recommend a large pie pan and a cold basement