METHOD OF AND APPARATUS FOR PREPARING A FROTHY COFFEE BEVERAGE, ESPECIALLY FOR HOUSEHOLD USE

In a method of preparing a frothy coffee beverage, especially for household use, comprising the steps of heating water in a closed space compartment, generating steam from the water, pressing water by the means of the steam generated through a batch of ground coffee for preparing a basic coffee beverage and accelerating the stream of the prepared basic coffee beverage to speed in the range from about 2 m/s to about 30 m/s before collecting it as a frothy coffee beverage at the outlet of the space compartment, the novelty lies in carrying out the heating step up to transferring a limited amount of heat energy to the water by creating conditions limiting heat transfer in water and/or by stopping the heating process during preparing the basic coffee beverage and the pressing step by the application of low pressure steam and at least one opening capable of widening and in arranging an impacting surface in the space for collecting the accelerated basic coffee beverage leaving the outlet of the space compartment. The proposed apparatus comprises a vessel (1), a cover (12) sealing the vessel (1), a holder (2) for coffee, at least one filtering element (10), an outlet pipe (15) and a constriction on a part of the length of the outlet pipe (15) for accelerating a stream of a pressurized liquid to speed in the range from about 2 m/s to 30 m/s, wherein the outlet pipe (15) is equipped with a self-regulating membrane valve system having at least one opening (24) of non-linear operation capable of closing the outlet pipe (15) until pressure of the pressurized liquid reaches a threshold value. L'invention concerne un procédé permettant de préparer du café mousseux, destiné spécialement à un usage ménagé et comprenant les étapes suivantes: chauffage de l'eau dans un compartiment fermé; génération de vapeur à partir de ladite eau; passage de l'eau, sous l'effet de la vapeur générée, à travers le café moulu, produisant un café de base; accélération de la vapeur dudit café de base pour qu'elle atteigne une vitesse comprise entre environ 2 m/s et environ 30 m/s, le café étant recueuilli sous forme de café mousseux à la sortie du compartiment. La nouveauté de l'invention réside dans le fait que l'étape de chauffage est exécutée de façon à transférer une quantité limitée de chaleur à l'eau, par création de conditions limitant le transfert de chaleur à l'eau et/ou par arrêt du processus du chauffage pendant la préparation du café de base, et que l'étape de passage de l'eau à tr