Most of your wine shop clients are likely to have heard of vertical tastings, but few will have heard of diagonal tastings. That’s because I just made them up. (I think) [level-members]
Actually, I’m sure someone else must have had the same idea already, since it’s hardly rocket science. The concept is simple: take a varietal and find different expressions of it from around the globe. Encourage them to do side-by side tastings of these wines and compare them. In the process, you’ll also be able to introduce your wine shop customers to the different ways wines are labeled and referred to in different regions and countries.
A note on format: for a person or couple who will be tasting by themselves, a six- or eight-bottle flight doesn’t make much sense. In those cases, I love suggesting a rotating weekly tasting. The first week, they taste wines A and B and then finish those bottles over the course of the next few days. The next week compares wine B to wine C, and so on until you’re back at the start and wine F (if it’s a six-bottle flight) is poured alongside wine A.