Addition of lees from base wine in the production of Bombino sparkling wine

In this paper, we explored an innovative and sustainable technology to improve the sensorial characteristics of traditional sparkling wine. Different volumes of lees, recovered from the first fermentation, were included into the "liqueur de tirage" for the second fermentation of Bombino grapes base wine. Proteolysis evolution was compared to that of traditional Bombino grapes sparkling wine over 18 months after "dégorgement", using combined liquid chromatography techniques and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of peptides in the size of 1500-3000 Da range. The addition of lees exhibited a clear impact on proteolysis, most likely due to the hydrolytic enzymes released by yeast autolysis. The profile of volatile organic compounds was assessed by gas chromatography-MS, foam stability, and the sensory traits were both evaluated by a panel of trained testers. The sensory traits were positively influenced by the addition of lees up to 60 mL/L base wine. Therefore, changing the amount of lees addition can be used to modulate the aromatic composition of sparkling wine in an attempt to improve it, and this also allows the shortening of ageing time.