Or tea. Probably the hackers second choice.
Munich: human-made espresso and beer. I haven't seen much tea.
Düsseldorf: machine-made espresso, Club-Mate and a variety of tea.
Don't know what they drink in Frankfurt.
The tea drinkers in Düsseldorf are not yet very sophisticated. What most of them failed to understand: absolutely excellent Japanese green tea is available - due to s strong Japanese community.
Many of these trends are actually from Hamburg. The CCC originated in Hamburg. New drinks like the Flora Power mate and 1337MATE are from Hamburg.
http://www.spiegel.de/netzwelt/web/leetmate-hackerbrause-aus...