Varietal thiols levels and sensory effects in South African Colombard wines

Abstract

The levels of varietal thiols and the role these compounds play in Colombard wine have not been investigated in detail. This study assessed the levels of the varietal thiols 4-methyl-4-sulfanylpentan-2-one (4MSP), 3-sulfanylhexyl acetate (3SHA) and 3-sulfanylhexan-1-ol (3SH) and their sensory effects in 24 young South African Colombard wines. Levels of 3SHA and 3SH were, in general, in line with those previously reported in South African Chenin blanc and Sauvignon blanc wines. Levels of 4MSP were, in general, found at a narrower range than those reported for Sauvignon blanc wines. Twelve of these wines were also sensorially analysed by a panel of wine industry experts. Aroma descriptors, such as guava, passion fruit, sweat and tomato leaf, which have previously been linked to 3SH and 3SHA, were also found, especially in the wines containing higher levels of these two compounds. Good correlations between 3SHA and sweat and guava were found. This study contributes to the knowledge of varietal thiol levels and their role played in 24 Colombard white wines. It could also lead to wine producers adapting their winemaking g practices to increase levels of varietal thiols if the aroma characteristics linked to these compounds are sought after in this single cultivar wine.