Single-circuit / single-circuit system

Espresso machines that are called single-circuit or run with a single-circuit system have a water circuit installed in the portafilter. Specifically, this means the following: In a single-circuit machine, the water is heated and then used through the same system for both espresso preparation and milk frothing. The single-circuit is ideal if you only want to prepare espresso. For the catering trade, on the other hand, a dual-circuit machine is indispensable.