## 2 Materials and Methods
### Must and Wine Analysis  
7.1 Measurements of Biochemical Parameters by High-Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC)  
Sugars, ethanol, glycerol, and acetic, lactic, malic, and tartaric acids were analyzed on an HPLC system (Agilent 1260 Infinity, Agilent Technologies, Santa Clara, CA, USA) equipped with a UV (ultraviolet, G1314F) and a RI (refractive index, 1260 Infinity II) detectors in series. Data acquisition and analysis were performed using the supplied instrument software (Agilent OpenLab CDS Chemstation v.A02.09). The mobile phase consisted of 0.65 mM H\({}_{2}\)SO\({}_{4}\) and was filtered (0.22 \(\upmu\)m, Nylon, Millipore, Burlington, MA, USA) before use. A 500 \(\upmu\)L sample was mixed with 4.5 mL of mobile phase and \begin{table}
\begin{tabular}{c c} \hline
**Primer Name** & **Primer Sequence** \\ \hline UnivSeq\_EF983F & gcagtcgaacatgtagcctaggtcacGCYCCGCAYCGTAYTYT \\ \hline UnivSeq\_983F2 & gcagtcgaacatgtagcctagcgtcacGCYCCGCAYAGAGAYTTYAT \\ \hline UnivSeq\_1567R & tggatcatctgtgcagcatcatcatcgtagACHGTRCCRATACCCRATCTT \\ \hline UnivSeq\_1576 RP & tggatcatctgtgcagcatcatcatcgtagACHGTCCRATACCGGARATCTT \\ \hline Univ\_ABx & CCATTCTCATCCCTGGTCTCCCGACTCAGI Barcode X \(|\) gcagtcgaacatgtagcctagcctacggtcac \\ \hline Univ\_ABC01 & CCATTCATCCCCGGTGTCTCCCGACTCAGCTAAGGTAACggctaacatgtagcctagcctacggtcacggtcac \\ \hline Univ\_trP1 & CCTCTCTCTATGGGACGTCGGTGTATtggcatcatgtgtgcagcatcatcatctgtg \\ \hline \end{tabular}
\end{table} 
Table 1: Primers used in amplicon-based sequencing (cellar-scale experiment). purified using a commercial solid-phase extraction cartridge loaded with 200 mg of sorbent (Waters Oasis HLB 6 cc, Waters AG, Baden-Dattwill, Switzerland). A 20 \(\mu\)L sample was injected and separated at 80 \({}^{\circ}\)C on a PS-DVB phase (Aminex HPX-87H, 300 \(\times\) 7.8 mm, Bio-Rad, Cressier, Switzerland) at a flow rate of 0.5 mL/min. Sugars and glycerol were quantified using a refractive index detector, while acetic, lactic, malic, and tartaric acids were quantified using a UV detector at 210 nm. The method for volatile analysis was adapted from [PERSON] et al. [24]. All chemical standards (acetaldehyde CAS 64-17-5, ethyl acetate CAS 141-78-6, methanol CAS 67-56-1, 2-butanol CAS 15892-23-6, 1-propanol CAS 71-23-8, 2-methylpropanol CAS 78-83-1, 1-butanol CAS 71-36-3, 2-methylbutanol CAS 137-32-6, 3-methylbutanol CAS 125-51-3, ethyl lactate CAS 687-47-8, and 1-hexanol) were provided by Merck (KGaA, Darmstadt, Germany). HPLC-grade ethanol was also purchased from Merck. Deionized water (>18 M\(\Omega\)) was obtained using the Millipore Treatment System (Millipore). Whiskey control congeners LGC 5100 were purchased from LGC (UK). Sparkling samples were degassed prior to analysis, and samples containing more than 20 g/L sugar were distilled prior to analysis. Samples were transferred to 1.5 mL vials, and 1 microliter was injected into the GC-FID. Standards and blanks were prepared in a water-ethanol solution containing 13% ethanol. All GC separations were performed on an Agilent 7890B gas chromatograph equipped with a 7693 autosampler. High-purity hydrogen was obtained from HG PRO LN (LNI Swissgas, Versoix, Switzerland). The capillary column was an Rt-WAX, 60 m \(\times\) 0.53 mm i.d, 1.0 um thickness (Restek, Bellefonte, PA, USA), and the injector temperature was set at 100 \({}^{\circ}\)C. The oven was programmed at 35 \({}^{\circ}\)C for 5 min, increased at 1 \({}^{\circ}\)C/min to 65 \({}^{\circ}\)C, and then increased at 20 \({}^{\circ}\)C/min to 240 \({}^{\circ}\)C, followed by 5 min at the final temperature, for a total run time of 48.75 min. The FID temperature was 250 \({}^{\circ}\)C. The split ratio was 10:1, and the injection volume was 1 \(\mu\)L. The volatile compound was determined by direct injection. First, a response factor (RF) was calculated for each compound analyzed in a sample using standard solutions.