I encountered an H2S problem when I made wine from chardonnay grapes that were sprayed with sulfur. The sulfur residue could be seen on the grapes. Of course the H2S may have been caused by some other reason and the problem was resolved by aeration.
I wonder how a spray program of sulfur and copper could affect winemaking. Does residual amounts of sulfur on grapes contribute to free SO2 and H2S in wine? What effects does residual amounts of copper have on wine? thanks Sarge