The pH adjustment of Vitis amurensis dry red wine revealed the evolution of organic acids, volatomics, and sensory quality during winemaking

Abstract

To produce quality dry red wines with high-acidity grapes of Vitis amurensis, an experiment was designed to adjust pH during winemaking by adding KHCO₃ at two time points and two pH levels in conjunction with malolactic fermentation (MLF). The organic acids and volatiles were detected by HPLC and GC-MS separately, combing with the color characteristic and sensory evaluation, we investigated the quality of V.amurensis wines under pH adjustment. Results showed that the pH adjustment weakened the wine color slightly but helped to initiate MLF. The low pH value of alcoholic fermentation favored the development of esters and higher alcohols. Higher pH levels promoted a sufficient MLF and enhanced the global aroma levels by 1.14-1.25 times, which led to higher sensory scores. In conclusion, KHCO₃ addition and MLF improved the quality of V. amurensis dry red wines, chemical addition after alcoholic fermentation was more effective for cold regions.

Keywords: Aroma; Deacidification; Grape and wine; Organic acid; Sensory evaluation.