Impact of closure system and sulfur dioxide management on the oxidative evolution of Timorasso wine

Abstract

When a winemaker considers which closure to use for a specific wine, they must evaluate several factors, including the wine’s expected longevity and its shelf life after leaving the cellar. However, the choice isn’t limited to whether the closure can preserve the wine’s aroma from oxidation over time, but also influences oxygen permeation, with consequences for the need for exogenous antioxidants, particularly sulfur dioxide. This study investigated the influence of bottle closure type and sulfur dioxide (SO₂) concentration on the chemical and sensory evolution of Timorasso (Derthona 2022) during bottle aging. Eight closure systems with different oxygen transmission rates (OTR) were evaluated, including four screw caps with differentiated OTRs, beeswax, Nomacorc Reserva, DIAM 10, and natural cork. Wines were bottled at three initial free SO₂ levels (15, 25, and 35 mg/L). Bottle evolution was monitored after 1 year through routine chemical analyses, colorimetric measurements, and targeted quantification of 37 carbonyl compounds using HS-SPME-GC-MS/MS, following the method described by Piergiovanni et al. (1), and was complemented by a technical sensory evaluation. Results showed that both closure oxygen permeability and initial SO₂ concentration significantly influenced the kinetics of sulfur dioxide depletion and the formation of oxidation markers such as aldehydes and ketones associated with oxidative processes. The differences between closure types were most pronounced at the lowest SO₂ level (15 mg/L). At these low levels of free sulfur dioxide, it is more evident that some closures are more suitable to limit the formation of oxidative markers and preserve the wine’s freshness. Colorimetric parameters and carbonyl profiles were consistent with the observed chemical trends. Sensory evaluation supported the analytical findings, revealing clear relationships between chemical stability and aromatic expression, particularly regarding freshness, fruit character, and overall aromatic intensity. Overall, the results confirm the critical role of closure selection and SO₂ management in modulating oxidative evolution in bottled white wines. Appropriate combinations of closure type and sulfur dioxide level can enhance the longevity and quality of Timorasso wines, providing practical guidance for precision enology and bottle-aging strategies.

References

1. Piergiovanni, Maurizio, Silvia Carlin, Cesare Lotti, Urska Vrhovsek, Fulvio Mattivi. 2024. ‘Development of a Fully Automated Method HS-SPME-GC-MS/MS for the Determination of Odor-Active Carbonyls in Wines: A “Green” Approach to Improve Robustness and Productivity in the Oenological Analytical Chemistry’. Journal of Agricultural and Food Chemistry, 72, 1995-2007. https://doi.org/10.1021/acs.jafc.2c07083