Recently published AWRI research has shown that the formation of reductive aroma compounds (such as hydrogen sulfide, methanethiol, ethanethiol and their corresponding thioacetates) is significantly affected by treating wines with O2 in the early stages of fermentation. In fact, the formation of some of these compounds in a Shiraz wine was completely eliminated through careful O2 dosage early in fermentation. These wines showed desirable red and dark fruit aromas when assessed by a sensory panel.
Commonly used remediation treatments were also assessed for their effectiveness in removing ‘reductive aromas’ from wines that had been treated reductively. Early copper fining was the most effective treatment; however, none of the treatments were able to produce wines with sensory profiles similar to wines treated oxidatively during fermentation.

Bekker, M.Z., Day, M.P., Holt, H., Wilkes, E., Smith, P.A. 2016. Effect of oxygen exposure during fermentation on volatile sulfur compounds in Shiraz wine and a comparison of strategies for remediation of reductive character. Aust. J. Grape Wine Research 22(1): 24–35.