Biersteuer
Biersteuer is a tax that is paid on beer in Germany. The level of tax is based on the gravity of the beer, measured in Grad Pluto, which is effectively a measurement of the amount of sugar and thus ethanol that the beer contains.
The tax is included in the price of beer when you buy it, and is collected by the government from the brewers.
Homebrewers, whilst not having to pay the tax provided that they do not produce more than 2 hectolitres per year, are still required to register their brewing activities with the customs office.
Alcohol-free beer is not usually taxed in this way, although mixed drinks such as shandy (eg. Radler) are.
To hear a simple explanation and a short discussion in German, listen to the podcast:
(Press the “play” button to listen to the podcast)