I measured the copper concentration in distillation of grapes’ fermented must using the small alembic unit 4210. This was carried by a colleague of mine in the Chemistry Dept. of our University. This unit was used up to now for more than 10 distillations.
The copper concentration found was: 2.07ppm which is equivalent to 2.07mg/lt. This is the upper limit of the EC for drinking water (of course for alcoholic drinks this concentration is within safe margins).
If the spirit was passed through a simple BRITA water purifier (5 times) this concentration is reduced to 0.04ppm!
Testimonial By I.E., 27-10-2006