This has been a huge topic recently, and as harvest in the Northern Hemisphere approaches, it's on everyone's minds. Wine faults are known as the presence of a chemical compound, or combination of compounds, that detracts from a wines’ quality. This expansive definition can be narrowed to the most common types of faults found in finished wines such as Brettanomyces (Brett), Trichloroanisole (TCA or cork taint), Reduction, oxidation, volatile acidity, and the more contemporary hot issue of smoke taint. Each of these flaws bring unique changes to the aromas and flavors of the finished wine as well as the structural components. Diligent practices with a strong focus on sanitation can be effective in avoiding these common faults. By relying on both sensory evaluation and chemical analysis, a winemaker can identify these faults if and when they occur and work to correct them by early detection.
Let's examine smoke taint as it has been a growing concern in recent vintages around the world.
Grape exposure to smoke can result in undesirable aromas such as ash, burnt wood, and medicinal aromas. The risk of smoke exposure causing a perceptible taint in wine is a function of the stage of growth, the variety, and the concentration and duration of exposure to smoke. Winemakers have little to no control over wildfires that cause smoke that in turn affect vineyards, but may be able to combat them with a few techniques. Limiting skin breaking by hand-harvesting, whole bunch pressing, and separating press factions can reduce the effects of smoke taint in a finished wine. One may also experiment with fining agents that are non-selective, such as carbon, to reduce the effects. The use of oak chips and tannin adjustments may also be used in conjunction with the previous techniques for the best approach. These of course are all reactive, outside of planting the vineyard in an area not prone to wildfires, harvesting (if possible) before the fires break out, and high elevation plantings are the only real ways to avoid smoke taint completely.
Smoke taint and its effect on wine quality is currently the buzz topic among scientists, media, winemakers, and researchers as wildfires have become a vintage concern from California to Australia. The Australian Wine Research Institute (AWRI) has completed many studies on how to avoid and detect smoke taint by identifying these risk factors and reactions to prevent and repair from future smoke taint.