Vertical tastings consist of tasting the same wine, which consists of the same winery, vineyard designation, and varietal from several years. You can create your collection of wines for vertical tastings by collecting the same wine as it is released each year. The bottle should be stored until a minimum of three vintages are represented.
On the other hand, you can purchase the bottles from a winery that contains multiple vintages of a particular wine.
Source: Tri-City Herald, December 2019