The Effects of Pre-Fermentative Treatments on the Aroma of Krstač and Žižak Wines

Pre-fermentative treatments are essential in winemaking, as they significantly influence the quality and stability of white wines in particular. The synthesis of many compounds obtained from yeast, such as higher alcohols and esters, is influenced by the type and concentration of aromatic precursors present in the must, especially amino acids. Clarification has a positive effect on wine quality, mainly by improving organoleptic properties, with flavour being the most affected. In this study, the influences of different static settling times, different pressures during must extraction and the addition of different bentonite concentrations to the must on the aroma of wines from the autochthonous grape varieties Krstač and Žižak were investigated. The identification of aromatic compounds in the wine was performed using GC/FID-MS analysis. Wine subjected to the longest static settling time (30 h) showed the highest concentration of esters. Krstač wine, which underwent a 30 h of settling, was characterised by an increased concentration of esters, such as isoamyl acetate, ethyl decanoate and ethyl hexanoate, while Žižak wine was characterised by the presence of 2-phenylethyl acetate and isoamyl acetate. The total fatty acid content in Krstač wine obtained by pressing was higher (14.90 mg/L) than in wine produced from free-run juice (8.04 mg/L).