Smoke taint in wine is a relatively rare yet significant issue, particularly relevant in regions prone to wildfires. Understanding this phenomenon is crucial for wine enthusiasts and professionals alike.

The smoke can influence the wine's quality, making it taste like an ashtray. (Credit: DallE)

Here's an exploration of what is smoke taint, how it occurs, and its implications for winemaking.

The Nature of Smoke Taint

Smoke taint occurs when grapes are exposed to smoke during their ripening stage. The contact with smoke can result in the formation of undesired tastes and scents, commonly referred to as volatile phenols, like ashtray. The compound primarily responsible for the taint is Guaiacol.

Wildfires near vineyards, especially towards the end of the growing season, are typically responsible for this. The taint only affects the grapes of the current harvest and does not carry over to subsequent seasons.

One critical aspect is that smoke taint is not detectable in the grapes themselves. It only becomes evident during the winemaking process.

The Rising Concern

Regions with drier climates have seen an uptick in such events, making smoke taint more common than before. It is estimated that wildfires will become more common by 15-70% by 2050. The period between veraison (when grapes change color) and harvest is particularly sensitive.

In recent years, it has become more noticeable and influential. Studies show that there may be more bushfires, which increases the chances of smoke taint.

Detection and Response

Consider a scenario: a winemaker in Australia, suddenly sees smoke on the horizon from a nearby wildfire right before harvest. This situation highlights the unpredictability and urgency of addressing smoke taint. While smoke taint can be undesirable, it's interesting to note that in other products like Islay Whisky, German Rauchbier, or certain cheeses, smoke is a desired quality. However, affected wines can lose some quality due to smoke exposure.

In the winery, it is possible to observe an increase in Guaiacol levels with maceration time. This means red wines are more susceptible than whites. Techniques like whole bunch pressing can mitigate the effects to some extent.

Searching for Solutions

The Australian Wine and Research Institute (AWRI) has conducted trials, including washing grapes, to remove smoke taint, but these efforts have been largely unsuccessful.

One method involves using an adsorptive resin in the wine, which can remove smoke taint but also diminish the desired fruity and floral notes we love. This approach is a trade-off between reducing taint and maintaining wine quality.

The Complexity of Smoke Taint

Wine's complexity extends to its faults, including smoke taint. Guaiacol levels can gradually increase over time, enhancing the smoke flavor. This compound is released during fermentation, making early detection in vineyards challenging.

The interaction of smoke compounds with grape sugars and the release of these compounds during fermentation add to the complexity. Enzymes in our saliva can break down these compounds, suggesting that yeast action is crucial in understanding and potentially mitigating the effects of smoke taint.

Smoke taint in wine is a complex issue that combines agricultural challenges, climatic factors, and chemical complexities. While rare, its impact can be significant, affecting the quality and character of the wine. The wine industry continues to seek effective ways to detect and manage this taint, balancing the preservation of desired wine flavors with the removal of unwanted smoke characteristics. For wine enthusiasts, understanding smoke taint is part of appreciating the intricate journey from vineyard to glass.

Learn next about cork taint in the first part of our "Wine Fault" series.

Peter Douglas