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Selected Publication:

Nauer, S; Patzl-Fischerleitner, E; Philipp, C; Hann, S; Eder, R.
(2021): Investigation of the influence of enological factors on the Rotundone concentration of wines of the variety Gruner Veltliner
MITT KLOSTERNEUBURG. 2021; 71(3): 222-239.

In the present work, the effects of classical oenological parameters and measures such as fermentation temperature, maceration time, sulphurisation (mash/young wine), must clarification and addition of yeast nutrient salt on the concentration of rotundone were examined by means of statistical experimental design. Three independent test series (A, B, C) based on a full factorial g2(2) experimental design in a scale of 25 liters each were carried out over two years (2011, 2012). An analysis of variance (ANOVA) was carried out as part of the statistical evaluation of the rotundone content and data were evaluated using a Pareto diagram, half-normal plot, main effect diagram and interaction diagram. For the parameters mash standing time and fermentation temperature tested in the context of experimental plan A, significant effects on the rotundone content could be determined for 2011, the same trend can be seen for 2012, but the differences at significance level 0.05 were not significant. A higher fermentation temperature resulted in higher rotundone contents, while a maceration period led to a reduction in both 2011 and 2012. The parameters mash sulphurisation and young wine sulphurisation tested in experimental plan B showed controversial effects in the two vintages. In the experimental year 2011, both higher mash and young wine sulphurisation resulted in lower rotundone contents, while in the experimental year 2012 opposite effects were observed. In the course of test plan C it was found that the addition of yeast nutrient salts led to a slight reduction in the rotundone content in both years, while the effect of must clarification in the two years was the opposite, with a significant reduction in the rotundone values analyzed in 2012 while in 2011 a non-significant, small increase was noted. In summary, it can be said that a higher fermentation temperature (23 degrees C), no maceration time, no mash sulphurisation and no need to clarify the must lead to higher rotundone contents. These results can be explained in agreement with literature and, among other things, by the hydrophobic character of rotundone. It is thus evident that the development of the peppery aroma of wines of the 'Gruner Veltliner' variety can be enhanced by the selection of suitable oenological measures.
Authors BOKU Wien:
Hann Stephan

Find related publications in this database (Keywords)
factorial design
maceration time
fermentation temperature
mash sulphurisation
young wine sulphurisation
must clarification
yeast nutrient salt addition
aroma analysis

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