If you haven’t had Absinthe it’s not for the meek; and it is an acquired taste. “Acquiring” that taste is not always possible. Quality of absinthe is also of concern. The worst absinthe may taste a bit like the better product, but usually doesn’t involve the complicated process a sugar cube, ice, special slotted spoon and a specific pouring regimen. The worst stuff: straight up, is like highly alcoholic, liquid, strong, licorice. The best; served properly, is a lot more delicate of a flavor with the addition of fennel and other spice-like flavors.
To make it more palatable for some, in Italy a measure of absinthe is poured into a glass of beer.
Absinthe, at 45%–74% ABV, is an anise-flavoured spirit that dates back to at least the 18th Century, derived from herbs, including the flowers and leaves of the herb Artemisia absinthium, . You may know it as wormwood. The chemical thujone exists in small quantities, so it may have mild psychoactive properties. It is green.
Historical note: the French used it as a treatment for malaria for their troops in the mid-1800s. No proof of medicinal value exists, but the Professor suspects an abundance of absinthe may have made malaria a bit more tolerable. A bit more, almost fun? A lot more then no more malaria, no more problems: no more soldier.
Since most absinthe put in beer is added straight up: unlike the light lager used for the beverage mentioned in the link provided above, the Professor suggests using a dark beer with a lot of character/deep roast and body to counter balance the strong absinthe flavor. A Strong Scotch Ale: highest shilling, may work. A barley wine may be a bit too sweet. Experimentation is called for. The Professor suggests starting with a teaspoon of absinthe, at best, then adjust to taste.