The inspection teams control the 31-hectare festival site to ensure that the so-called "mass" glasses contain a full liter of beer. They do this by conducting spot tests, during which they measure the contents of a newly poured glass of the beverage.
The surface of the beer must be no more than 15 millimeters below the liter mark on the glass after settling for four minutes (I.e., minus the foam). If it is measured and found wanting, penalties range from exuberant fines to barring the license holder from selling beer again for a time period up to one year!
The head of the local authority responsible for these inspections, Wilfried Blume-Beyerle, said that their inspectors are very well trained, and some years they have tested as many as 1535 glasses of beer within the first five days of the festival. Although they did come across some short measures, they were very few compared to the amount of glasses poured.
