INFLUENCE OF THE TYPE OF FERMENTER ON THE CHEMICAL COMPOSITION OF VRANEC AND MERLOT WINES

Abstract

In this study, red wines from V. vinifera L. cv. Vranec and Merlot (harvest 2021) have been produced by three different fermentation methods, applying classical, roto and punch down fermenters, in order to study their influence on the wine quality. The chemical parameters that confirm the basic wine quality have been determined, including alcohol, dry extract, specific density, reducing sugars, total and volatile acidity, pH, free and total SO₂. The Vranec wines contained relatively higher content of alcohol compared to the Merlot wines, due to the higher content of sugars in the grapes. Wines produced with roto fermenter presented higher values of dry extract and total acidity, compared to the wine produced with classical and punch down fermenters, which confirms that roto fermentation is most suitable for production of complex and structured wines. The alcohol content in all wines ranged from 12.08 to 12.4%, total acidity was between 5.8 to 6.3 g/L and the dry extract from 39 to 45 g/L, while the content of volatile acidity was in range from 0.41 to 0.45 g/L. All wines were dry wines, with content of reducing sugar lower than 4 g/L and all of them were well protected from the oxidation. It was concluded that the type of fermentation affected the wine quality, confirming that applied wine technology is important for production of quality red wines.