The Industry's Leading Publication for Wineries and Growers
Copper sulfate (CuSO4) is a fining agent used to remove unpleasant hydrogen sulfide (H2S) and other "sulfide-like" off aromas in wine. The hydrogen sulfide is generally described as rotten-egg-like off aromas.H2S is volatile natural product of the fermentation and it can be present into the wine as mono-mercaptans (sulfides), which can be treated with copper or poly-mercaptans (disulfides) which will not react with copper, so deal with the problem as soon as it is detected. Copper when added to wine containing "sulfide-like" off aromas immediately reacts with H2S and form copper sulphide, immediately. If the copper ions is not removed from the wine after the treatment with the proper fining agent or filtered out, a haze may appear. Most of the time copper is added to the wine in the form of Copper Sulfate s(CuSO4•5 H2O), also known as Copper Sulfate solution.
To avoid over adjustment, copper lab trial should be performed.