Correlating Sensory Assessment of Smoke-Tainted Wines with Inter-Laboratory Study Consensus Values for Volatile...

Area of Science:

• Enology
• Analytical Chemistry
• Viticulture

Background:

• Wildfire smoke exposure poses a significant risk to vineyards, potentially imparting undesirable flavors and aromas to grapes and wine.
• Accurate and precise analytical methods are crucial for quantifying smoke taint and understanding its impact on wine quality.

Purpose of the Study:

• To assess the interlaboratory variability in the quantitative analysis of smoke-tainted wines.
• To correlate analytical measurements of smoke taint markers with sensory evaluations.
• To determine the reliability of different smoke taint compounds as indicators of perceivable taint.

Main Methods:

• Quantitative analysis of smoke-tainted wines by nine commercial and research laboratories.
• Comparison of analytical results for volatile phenols (e.g., guaiacol, cresols) and their glycosidically bound forms.
• Correlation analysis between interlaboratory consensus values and sensory panel data.

Main Results:

• Significant interlaboratory variance was observed for most smoke taint markers, particularly cresols and glycosidically bound compounds.
• Free guaiacol analysis showed higher accuracy (94 ± 11%) in model wine but was less precise than desired.
• Free cresol concentrations demonstrated a strong correlation with sensory perception of smoke taint, offering a reliable predictive measure.

Conclusions:

• While single-laboratory data can quantify smoke taint, direct comparison of results across different laboratories is not recommended due to high variability.
• Free cresol concentrations are a robust indicator for predicting the risk of perceivable smoke taint in wine.
• This predictive capability for free cresols overcomes limitations of guaiacol, which occurs naturally in grapes and oak.