Wine fining agent: Copper Sulfate
a last-minute rescue agent to get rid of that rotting smell from wines and ciders.
CuSO4.5H20 Pack contains, 2gm of this fining agent. It removes the H2S, the rotten egg-like smell that comes from stressed yeast (which is usually caused by a combination of lack of yeast nutrients, high temperature and too much sugar levels in the primary). Highly recommended for those who use baker’s yeast instead of wine or brewing yeast for fermenting grapes and fruit juices.
Use sparingly (copper toxicity) and follow the expert fining agent guide for the exact quantity and usage instructions.