2.3. Wine Sampling and Storage

After 4 months maturation, 10 L of wine was sampled into a 10-L canister from every treatment’s repeats. The barrels were then subsequently filled with the same wine from a stainless-steel tank. The free SO₂ was also adjusted to 35 mg/L with Sterisol (EnolTech, EVER INTEC, Australia). The samples were transported to the experimental cellar at the Department of Viticulture and Oenology, University of Stellenbosch. The free SO₂ levels were measured for every canister and increased to 35 mg/L with a 2.5% SO₂ solution if required. The canisters were stored at −4 °C for two weeks before the wine was bottled in 750 mL green Burgundy bottles (Consol, XPRS, South Africa) and closed with saranex screw caps (CDS Vintec, South Africa). After bottling, the wines were stored at a constant 4 °C until the time of sensory analysis. This was done to prevent sensorial changes from happening.

After 9 months of maturation, samples were again taken using the same protocol as described for the 4-month sampling, except that 20-L samples were taken. A part of this, wine was used for immediate sensory analysis, with the rest kept at a constant 15 °C for another 6 months for further bottle maturation, which is a normal bottle ageing temperature.