A process of preparing a beverage from a beverage preparation chamber comprises the steps of feeding water to the preparation chamber (2) until a first pressure (P1) of at least 3 bar is reached, interrupting the flow of water to the preparation chamber, holding said preparation chamber (2) in a closed condition for a first time interval (t.sub.1), opening said outlet (3) of the preparation chamber (2) and delivering the thus prepared beverage.