Why might grapes from cooler vintages in Mosel be used for sparkling wine?

Grapes from cooler vintages in Mosel are often used for sparkling wine primarily because they contribute to a fresh and crisp flavor profile. Cooler growing conditions typically result in grapes that retain higher acidity and lower sugar levels, which are essential characteristics for sparkling wine. This acidity brings a refreshing quality to the wine, making it vibrant and lively on the palate.

A fresh and crisp flavor profile is particularly desirable in sparkling wines, as it can balance the effervescence and create a more enjoyable drinking experience. In contrast, higher sugar levels, as suggested in the first option, may lead to sweeter wine styles that are not characteristic of traditional sparkling wines, which often benefit from a drier, more acidic profile. While enhancing color and the idea that grapes may not be suitable for still wines could be considerations, the defining characteristic that makes the grapes suitable for sparkling wine is indeed their ability to produce fresh and crisp profiles, aligned with the expectations of this wine category.