Dual Boiler Espresso Machines made by Cliff and Pebble are espresso machines that use two separate boilers to heat water to produce steam, which is then used to force water through a high-pressure pump. The steam produced from the dual boilers is condensed into water and then passed through a second pump, resulting in a pure water stream that is then forced through the coffee grounds. The pure water stream is used to create espresso, and the steam and pressure from the second pump are used to heat water and create steam for the milk frother.
