PREVENTION AND TREATMENT OF REDUCTIVE AROMAS
Reduction in wines is one of the most common problems in winemaking. Hydrogen sulfide and other volatile sulfur-containing compounds are commonly produced during alcoholic fermentation, but they can also develop during storage and ageing, as well as after bottling. The aromas generated by these sulfur compounds are usually described as rotten egg, burnt rubber, skunky, burnt match, asparagus, onion and garlic. These compounds have low sensory thresholds. At times, when found below their sensory thresholds, they tend to mask and decrease aromatic qualities, without pointing to an obvious reduction flaw. Additionally, sulfur-containing compounds can impact mouthfeel and intensify other negative wine attributes such as bitterness and herbaceous characters.