Espresso coffee prodn. with froth formation by pressure - takes place in cylinder where adjustable pressurisation is applied to liq. extract before release from outlet

摘要

The coffee powder is fed through an opening at the base of a hopper into a horizontal cylinder where it is compressed by a piston into a relatively small space near the cylinder end. An extn. tube formed in the cylinder end connects the space to atmos. via a microsieve. The tube leads to a spring-loaded ball valve which can be adjusted by rotation of the threaded end of the outflow pipe screwed into the cylinder end. The coffee extract is thus pressurised before delivery so as to increase the quantity of froth produced and to improve the taste of the extract. ADVANTAGE - Formation of froth is enhanced in natural way without addn. of any impurities.