## 2 Materials and Methods  
### Winemaking Process  
Chardonnay (CH) and Xarel.lo (XA) grape varieties were used for the production of the studied cavas. For each grape variety, 100 kg of grapes harvested in 2018 was destemmed, crushed and distributed into 50 L stainless steel fermenters. The basic chemical composition of the mists was as follows: for CH, brix grade 16.9; nitrogen assimilable by yeast 297 mg/L; ammonium 122 mg/L; pH 3.41; total acidity 8.23 g/L expressed as tartaric acid; and malic acid 5.7 mg/L, and for XA, brix grade 16.3; nitrogen assimilable by yeast 193 mg/L; pH 3.15; total acidity 6.45 g/L expressed as tartaric acid; and malic acid 1.9 mg/L. During grape processing, 40 mg/L of SO2 (Sulphur 18, Agrovin S.A., Ciudad Real, Spain) was added to prevent oxidation and for microbiological control. The vinifications were carried out in duplicate for each variety on a pilot scale in the experimental VITEC winery. For each vinification, 26 L of must obtained from 40 kg of varied grapes was used (65% yield). The cold settling was carried out with active pectolytic enzymes (Endozym Eclair, AEB Iberica S.A.U., Barcelona, Spain) at 11 \({}^{\circ}\)C overnight and the alcoholic fermentation was carried out at a controlled and constant temperature (17 \({}^{\circ}\)C) in cold water baths. To carry out the alcoholic fermentation to obtain the base wine, five different commercial yeasts were used: three different strains from _S. cerevisiae_, Y1 (IOC 18-2007, Institut Oenologique de Champagne, Epernay Cedex, France) indigenous yeast selected from the Champagne vineyards, Y2 (Viacell Rhone 4600, Lallemand SAS, Blagnac Cedex, France) yeast selected by the Inter-Rhone Technical Service in the northern Cotes du Rhone region, and Y3 ([PERSON] Yseotm Lalvin, Lallemand SAS, Blagnac Cedex, France) indigenous yeasts selected by natural crossing, and two non-_Saccharomyces_ yeasts, Y4 (Flavia MP346, Lallemand SAS, Blagnac Cedex, France) pure culture of _Metschnikowia pulcherrina_ and selected from nature by the University of Santiago de Chile (USACH), and Y5 (Level Biodiva, Lallemand SAS, Blagnac Cedex, France) pure culture of _Torulaspora delbrueckii_. The addition of each of the yeasts was carried out as recommended by the manufacturer. The course of the fermentations was monitored by the consumption of sugar, and it was considered complete when the residual sugar concentrations were below 0.5 g/L. In all cases, fermentation began 24-48 h after inoculation and lasted about 10 days. After fermentation, base wines were sulphited to reach 30 mg/L of free SO2. After 24 h, wines were racked and clarified with the addition of 40 g/hL bentonite (Bentogran, AEB Iberica S.A.U., Barcelona, Spain). After that, and to carry out the second fermentation, base wines were bottled in glass bottles of 750 mL and, finally, cavas were obtained. For this, _S. bayanus_ (Uvaferm PMA, Lallemand SAS, Blagnac Cedex, France) was added in the triage solution. Tirage also contained 40 g/L adjuvant (Adjuvant 92, Station Oenotechnic of Champagne, France) and 20 g/L sugar (glucose). Finally, after disgorgement, cavas were aged on their lees for 18 months. Analyses were made in base wines (BW) just before triage, and in cavas after 18 months of aging on lees (18M).