Dual boiler with vibration pump | espresso machine
Dual boiler portafilter espresso machines with vibration pump. A boiler with a temperature of about 120° for steam and hot water and a separate smaller boiler with a temperature of about 93° for espresso. Dual boilers combine the advantages of single-circuit machines with those of dual-circuit machines. They are as precise in temperature as a single-circuit machine and offer the simultaneous and easy MIlch frothing of the dual-circuit machine. Both boilers can be precisely controlled on most models and can be set to the ideal temperature for the bean or milk foaming. Vibratory pumps are compact, inexpensive pumps that take about 4-5 seconds to build up pressure and require a counterpressure (coffee puck or dummy strainer). This creates an automatic, uncontrolled pre-infusion, which is sometimes an advantage with strongly fruity (sour) beans. They are somewhat louder than the more expensive rotary pumps. Perfect for espresso specialists and friends of foamed milk.