A new study by resarchers at USA Oregon State University looked at why some red wines, especially Pinot noir, can taste ashy or smoky if the grapes were exposed to wildfire smoke before harvest. When grapes are exposed to smoke, they absorb certain chemicals that later end up in the wine. These chemicals include volatile phenols and thiophenols, which can make the wine taste smoky, burnt or leave an unpleasant ashy aftertaste.
The researchers wanted to find out how much of these chemicals it takes for regular wine drinkers to actually notice the ashy flavour. They tested this using different styles of Pinot noir and different amounts of smoke-related chemicals. People tasted the wines and said whether they thought it tasted ashy.
They discovered that it doesn’t take much, just a tiny amount of these compounds, especially when both are present together. The stronger the smoky compounds in the wine, the less of the other, thiophenols, was needed to make the wine taste ashy.
They also found that the style of wine makes a difference. Wines that are lighter or simpler in flavour made the ashy taste easier to notice. More complex wines, for example, those fermented differently or with more grape skin contact, sometimes masked the ashy taste a bit better, but only when smoke levels were lower. At higher smoke levels, almost everyone could taste the ash, no matter the style.
