Underberg is a gentian-based digestive bitters aged in Slovenian Oak. When trying to describe its flavor to friends who are not hip to Amari, Fernets, or herbal liquors, one might describe it as similar to Jägermeister, with the herbs and bitterness amped up and the sweetness all but gone.
However, while that description may help novice imbibers get the gist, it is painfully over-simplified and does not do justice to the nuances of Underberg. This digestive uses herbs and botanicals from 43 different countries—complex flavors and aromas, to say the least. When taken after a large meal, it has magical digestive powers.