Wine & Spirit Education Trust (WSET) Level 1 Award in Wine Practice Exam

Sparkling wine is defined by its characteristic effervescence, which is the result of carbon dioxide gas being trapped in the wine during fermentation. This process can occur either in a single fermentation (as seen in some forms, such as Prosecco) or through a secondary fermentation (as in traditional method sparkling wines like Champagne). The presence of bubbles is what distinguishes sparkling wines from still wines, and it is this trapped carbon dioxide that creates the refreshing qualities and distinct mouthfeel associated with sparkling varieties.

The other choices do not accurately capture the essence of what sparkling wine is. Higher acidity is a feature common in many wines, both sparkling and still, but does not define sparkling wine specifically. Filtration is a winemaking process that can apply to many wines but is not related to the sparkling aspect. Lastly, while sparkling wine can be made from white grapes, it is not exclusive to them, as many sparkling wines use red grapes or a blend of both.