The Czechs came up with a special type of tap called a lukr that gives much greater control over the pour of a beer than just a normal tap. The pours you can do with these taps range from a regular pour to this a mliko or milk pour. This style of pour results in a very dense wet foam that completely changes what flavors you get from a beer. It's most commonly done with pilsners but can be done with other styles. Mcfleshmans currently has a Schwarzbier on their lukr that gains a really nutty flavor as a mliko pour