Abstract. In an experiment with Rosé wine, 27 different commercial yeasts were tested for their influence on the amino acid pattern of the wine. Amino acids are precursors for aromatic substances; therefore a large variation of the amino acid values in the wine was expected. Blaufränkisch grapes with 20 • KMW were matured in the cellar with 27 different commercial yeasts. The fermentation was carried out in 34l vessels. The wines were measured for amino acids using an HP 1200 liquid chromatograph and HP-FLD1100 according to Umagat. The wines showed 13.5% alcohol and little residual sugar. The measurement results of the amino acids of the different wines showed large variations. For example, the amount of the amino acid alanine in wine varied from 17 to 138 mg. In particular, the wines of the yeast Pino Type showed the highest amounts of alanine in comparison to the other fermented wines.

In this experiment, 27 different commercial yeasts were tested for their influence on the phenols of a rosé wine. The phenols depend primarily on the vine variety, cultivation and cellar processing. This experiment sought to clarify how great the influence of the yeast on the phenols is. Blaufränkisch grapes with 20 • KMW were matured in the cellar with 27 different commercial yeasts. The vinification was carried out in 34 l vessels. An HPLC Agilent Technology 1220 (RRLC) with a column of ZORBAX SB-C18 15 × 2.1 mm (1.8 µm) was used for the measurement. 5 µl of the sample were injected directly. The column oven temperature was 40 • C. The transient was 0.5% formic acid (pH = 2.3) and a gradient of methanol (3%, 4%, 14%, 30% and 70%). The detection took place at 280 and 320 nm. It was shown that the effect of yeast on phenols is low. There was a great influence on the chemical substance tyrosol. This is a phenol that can be formed by the yeast itself. The values varied between 5.4 mg and 13.2 mg/l. The already described influence of the duration of fermentation on tyrosol formation could not be confirmed.