“Struck flint” aromas in Chardonnay Wines

Struck flint/struck match/gun smoke/mineral aroma is considered desirable in some styles of wines, with this character sometimes evident in wines such as Burgundian Chablis and cooler climate barrel-fermented Australian Chardonnay. Phenylmethanethiol (benzyl mercaptan) is a potent sulfur-containing volatile aroma compound and is thought to be responsible for struck flint character in wine. However, few studies targeting this character have been done. To address this, over 70 commercially available white wines, mostly Chardonnay, were chemically analysed to establish the variability of phenylmethanethiol, and the wines were assessed by a sensory panel to indicate whether there might be a transition from struck flint aroma to a less pleasant sulfurous/burnt aroma.

There was also no information available on the effects of winemaking techniques and commonly used winemaking additives on the formation of phenylmethanethiol. Further investigations in model fermentations of its potential precursors benzaldehyde and hydrogen sulfide were conducted.

Source:
The lecture reproduced in this video was presented at en IVAS 2022 – In Vino Analytica Scientia
T. E. Siebert, D. Espinase Nandorfy, A. G. Cordente, L. Pisaniello, F. T. Watson, S. R. Barter, D. Likos, A. C. Kulcsar, I. L. Francis, and M. Z. Bekker (2022). Struck flint aroma in Chardonnay wines: what causes it and how much is too much?. IVES Conference Series, IVAS 2022. https://ives-openscience.eu/14260/