Influence of the ageing time on the quality of three kinds of cold-climate mountain grape brandy

Northeast China boasts abundant resources of cold mountain grapes. This study focused on three varieties of cold mountain grape brandy, Beibing Hong (BBH), Shuanghong (SH), and Zuoshanyi (ZSY), with varying ageing periods to investigate changes in their physicochemical properties, nutrients, and aroma compounds. Results showed that alcohol content and pH gradually decreased with ageing, while total acidity (including inorganic acids) increased. Specific organic acids declined over time, whereas polyphenolic compounds increased with longer ageing. Furthermore, the total quantity of aroma substances in all three brandies was positively correlated with ageing duration, with 18-month-aged BBH brandy exhibiting the highest content and the richest aromatic variety. Clustering analysis via heat maps revealed that brandies aged 12 and 18 months grouped together, showing that ageing time correlated positively with most esters and alcohols and negatively with acids. No significant variations were observed in the contents of terpenes, aldehydes and ketones among the three brandy varieties.