Stabulation (lees stirring) in must as a method for aroma intensification: A comparison with skin contact and a classical version of Traminer and Sauvignon blanc in Austria

Abstract

In the course of this study, stabilisation (lees stirring in unclarified must) with skin contact and classic white wine vinification were compared for the Sauvignon blanc and Traminer varieties in Austria. The test wines were analysed for the volatile substances esters, free monoterpenes and fruity thiols. Analytically, the stabilisation could only produce good results to a limited extent compared to the skin contact. In comparison to the 0-sample, however, some effects could be observed. The 3-mercaptohexanol concentrations were significantly increased with 7 days of lees stirring compared to the other variants (except 24 h mash standing time). It was also positive that the lees stirring showed effects on the content of free monoterpenes in the Traminer variety compared to the 0-variant. If this method is to be used successfully, however, some technical aspects of wine-making should first be clarified. Depending on the volume, at least one wine tank with cooling equipment is blocked for a week. Obviously, the cooling system must function properly in this tank. Furthermore, it must be emphasised that the constant stirring of the lees with an agitator could produce a high amount of fine lees, which could cause problems during must clarification. In this trial, stirring could only be done with the help of a glass rod, which reduced the mechanical stress many times over. If there is no stationary stirrer in the tank, it always has to be mounted and dismounted. This could also induce aroma losses through oxidation. However, if the winery has all these technical possibilities, stabilisation could be an issue. Compared to the maceration time, we see the greatest potential in increasing fruity thiols in the Sauvignon blanc grape variety.