A special form of wine tasting in which the quality of wines from a certain growing region is usually determined for a certain vintage, i.e. the same year. The "horizontal" refers to the time axis. Naturally, these are wines from different producers, but they should have rudimentary similarities in order to allow an objective comparison. These are, for example, the same grape variety or mixture of grape varieties(cuvée), the same ageing (for example, barrique ageing), the same taste (for example, dry) and the same quality standard (for example, top producers or a similarly assumed class). Of course, differences in quality between producers can also be detected. But just as well the wines can be a cross section of different (presumed) qualities.