In the middle of the kitchen is a machine in petrol. Its lever mechanism looks like it could be used to mint coins or to train arm muscles on it. But the La Marzocco Leva, as it is called, is a coffee machine. Its owner Friedrich Kautz, known to music lovers as the rapper Prinz Pi, is just explaining to German barista master Aylin Aslan how to extract an espresso from this thing – list price for the regular version: more than 13,000 euros. The smell of coffee wafts through the whole kitchen.