A vertical wine tasting is conducted by tasting a series of wines from the same winery, but produced during different years of vintage.  For example, you might conduct a vertical wine tasting of HV Cellars Pinot Noir from the vintage years 2004, 2005 and 2006.

Tasting the same type of varietal wines from the same wine maker and vinyard with the production year being the single variable allows people attending your wine party to realize how dramatic or subtle the nuances of wine can change from year to year.

There are many factors which contribute to the heritage of a wine's vintage, things like new barrels, weather, insects and other pests can have a direct effect on the outcome of a wine and make for interesting conversation... So try to obtain as much literature about the wine and possibly the wine maker's notes before holding your vertical wine tasting event so that your guests can discuss the possibilities about the causes for the differences between each vintage.

Holding a vertical wine tasting will enable you and your guests to get a better feel for a particular winery's style and composition and will fine tune your preference for wines and vintages.