Following up on a previous post: I made mine with a Montrachet cake from Apfelwein. It took off like a rocket and I did what I was supposed to do but the yeast still produced a crapton of H2S. Degassing and racking helped, but when it came time to keg the now clear nectar the sulfur nose was almost too much. I found
MoreWines Copper Sulfate Addition Procedure (on MoreBeer.com strangely) and decided to give it a try. While the document was correct it was rather rambling and not straightforward to follow. Still, good results.
After doing my bench tests I ended up using 0.6 ppm CuSO4. Since this is a level found to get rid of the H2S and no more, it should nearly all precipitate out as an insoluble copper sulfide. Even so,
the EPA's "action level" for copper is 1.3 ppm so I've added less than half of that.
The process was not difficult, and I saved a batch so maybe this will help someone else. All I ended up using was 1.53g of CuSO4 (still nearly all left over as a 1% solution), 6 baby food jars, a few oral syringes (the 1mL was the most helpful, free from pharmacist) and some distilled water.
I'm left wondering if the other method on that document, racking through a copper cane, would be easier and just as effective. As acidic as this is it might end up stripping too much copper and not be a good thing for those sensitive to it. SO many experiments, so little time.