Oh! I've assumed this was a common thing outside of Germany and the Netherlands! It's beer mixed with lemon juice. It's often around 2-3% in alcohol and is perfect as a refreshment after a warm day of cycling (hence the name)
Ah, the beer is mixed with lemonade - not with lemon juice.It's basically the German (Central European) variant of the British Shandy (not the Dutch one).
About 50/50 Beer and limonade (most often fizzy, but juices can also be used).
Edit: As @Heindijs said.![]()
A shandy, in other words,
They can be wonderful in summer, when served with a light lager, especially in the afternoon when anything stronger would leave you comatose, or, at the very least, somewhat sleepy.