Watching a Korean drama years ago playing in modern times, an installation in a coffee- bar intrigued me . It appeared to be a way of coffee-making used on Dutch trade-ships in 17th C. to Asia. Called "Dutch Coffee". Ice-brewed coffee taking hours . Still popular in Asia, very few know it in Holland. ( Although a certain coffee-chain sells "cold brew).
Looking on the net, S.Korea and Japan pop up most for using it.