Poktanju

A poktanju consists of a shot glass of soju or whiskey dropped into a pint of beer; it is drunk quickly.

[1] The consumer downs the cocktail quickly "then shakes the empty glass with the shot still inside to make a ringing sound, followed by applause of other drinking partners, and it is passed to the next person.

[6] "A foreigner traveling in Korea and socializing with the locals is likely to be bombarded with such cocktails, which have long been a hallmark of the Korean drinking culture".

"The welcoming ceremonies usually involve binge-drinking events, which generally take the form of all-night sessions in a bar downing boilermaker "bombs".

"Soju is distilled from rice, barley, and koji (a cultured grain), and cheaper brands are made from sweet potatoes".

[9] "Soju originated in 14th century Goryeo, when Mongol invaders led by Genghis Khan introduced the Levantine distilling technique from Arabia to the Korean Peninsula".

[8] The third theory is that the "current style of poktanju ― beer with a shot of whisky ― made its Korean debut in the early 1980s, at a meeting between prosecutors, policemen and journalists in Chuncheon, Gangwon province".