why not
Filter any particles out with cloth, then just boil the water for 10 minutes?

You'd get cleaner drinkable water with none of the ash and smoke!
(Greencloud Wanted to go fishing on, Wed 16 Nov 2011, 11:15, 2 replies)

That's what I've suggested.
This enables you to recoup all the water.
( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 16 Nov 2011, 11:26, closed)

I suppose there could still be the risk of chemical pollution - heavy metals, fertilisers, etc.
A filtration and rolling boil only kills off organic nasties.
(oneinthepink is at your cervix m'lady, Wed 16 Nov 2011, 11:27, closed)

that's true, but...
If you really want to be fussy about it, you could use some of your fire embers to make a charcoal filter instead of basic cloth. This would be the best you could manage without a properly manufactured filter.
The condensation method may keep chemical pollutants (depending on their specific type) as they would evaporate with the water and be recaptured with the condensation. Along with the ash and shite kicked up by the fire.

I'll grant that condensation is perhaps the easiest way to desalinate sea water though.
(Greencloud Wanted to go fishing on, Wed 16 Nov 2011, 13:31, closed)