The objective of this study was the characterization and the evaluation of the extracts of grape residues in the control of growth of Dekkera bruxellensis, an important yeast contaminant of the ethanolic fermentations. The raw material used was the residue of the wine processing (seed and grape skin) of Merlot and Cabernet grape varieties. The samples were characterized by the concentration of total phenolic compounds and by CGMS. The Minimal Inhibitory Concentration (MIC) experiments were carried out with different concentrations of the extracts (100, 200, 300, 400 and 800 mg / L) using the strain CCT7784 (CCA155) of D. bruxellensis. The alcoholic extracts of Merlot and Cabernet grape residues reduced yeast growth from 200 mg/L, but the reduction was greater with the Merlot grape extract. The phenolic composition of the ethanolic extracts of the Merlot and Cabernet grape residues, identified by the GC-MS technique, showed a predominance of the flavonoid epicatechin, suggesting that this compound participates expressively in the biological activity of these samples. The alcoholic extracts of grape residues showed potential products to be better investigated, both for their action on the microorganisms and their efficiency in fermentation conditions and cost evaluation.