Influence of grape and or vine leaf addition on the flavour of Grüner Veltliner wines

Abstract As a result of climate change, Grüner Veltliner grapes are expected to have a different composition, which will be accompanied by an expected reduction in the spiciness of the wines caused by the decrease in the concentrations of the sesquiterpene rotundone. Scientific efforts to develop solutions are essential, including research into partly unorthodox and non-authorised methods. In the course of the present work, a control variant was compared with the variants grape leaf addition and/or grape addition for the content of selected positive grape and fermentation flavours and the total phenol content in the Grüner Veltliner variety. The addition of leaves resulted in an undesirable reduction in rotundone. This variant also proved to be unsuitable due to the extraction of undesirable methoxypyrazines, in particular 2-isopropylmehtoxypyrazine, the extraction of 1-hexanol and the extraction of phenols. In contrast, the addition of grapes has shown that the rotundone content can be increased with a moderate change in fruitiness. There was also no change in the hexanol content with the grape addition variant and the extraction of methoxypyrazines was more moderate than with the leaf addition. However, this variant cannot be recommended due to the strong increase in phenolic compounds. Further research into the addition of grapes is recommended, although the addition of berries alone should also be considered in addition to the grape addition variant.