What is Boosted Boiler, and how does it set Espresso Series 1 apart?

Boosted Boiler is Fellow’s patented technology that combines the best features of a low thermal mass heater with a traditional boiler architecture. It means Espresso Series 1 has the thermal stability of a large commercial dual-boiler machine, but with a heat-up time of less than 2 minutes.

For those that want more details…

This is accomplished by controlling 3 independent heating elements in harmony. Water flows through the low thermal mass heater, into the mini-boiler, and then into the independently heated grouphead. This allows us to have a thermal bank to deliver water to the puck at the proper flow rate and temperature, just like a commercial machine, but without the excessively long wait. You can preinfuse with a flow rate of 1ml/s to 8ml/s, without sacrificing temperature stability. You no longer have to choose between giant boilers that take forever to heat up OR dumping cold water onto your puck for the first 5 seconds of the shot.