At the core of the 9Barista is its unique twin-boiler system, which provides stable brewing pressure and a constant brewing temperature of around 93 degrees. When the high-pressure boiler heats up to 179 degrees on the stove, the internal pressure rises to 9 bar.

At 9 bar pressure, the spring loaded valve opens, allowing water to flow from the high-pressure boiler into the coil heat exchanger.

As the high-pressure water from the first boiler passes through the coil, it cools from 179 degrees to 100 degrees while maintaining 9 bar pressure. The water then passes through the fin heat exchanger, further cooling to 93 degrees.