What is the labelling term used for sparkling wines that incorporate a blend of several vintages?

The labeling term for sparkling wines that incorporate a blend of several vintages is "Non-vintage." This term signifies that the wine is made using a combination of wines from multiple harvest years. Non-vintage sparkling wines are often created to achieve a consistent flavor profile and style that reflects the producer's house style, regardless of the variations that may occur from year to year.

In contrast, the term "Vintage" refers to sparkling wines made entirely from grapes harvested in a single year, which often showcase the specific characteristics of that particular vintage. "Single Vineyard" indicates that the grapes come from one specific vineyard site, focusing on terroir. "Reserve" typically refers to higher quality wines that may be aged longer, but it does not specifically indicate the blending of vintages. Therefore, "Non-vintage" is the correct descriptor for sparkling wines that are blended from multiple vintages.