Today in espresso school, the tech department pulled out an open housed Expobar Brewtus IV-Rotary Pump Espresso Machine. At first, it looked like an unsolved Rubik’s Cube to me as it had all the various parts of the internals labeled in different colors for demonstration purposes. I immediately became nervous because obviously our tech department had done their homework ahead of time and I had not (just like high school!).
Professor Todd Salzman took his time thoroughly explaining to us in great detail the engineering and operation of this dual boiler machine. We of course compared this model and its components to similar espresso machines like the Rocket Espresso R58 and the Izzo Alex Duetto II. This information was very enlightening and will enable me to give better answers and information to the many customers who call in inquiring about these espresso machines. Customers have very detailed, (mechanically speaking), questions about technical features that I now feel more confident answering after today’s lecture. For example, we discussed how the Expobar has a larger brew boiler than other dual boiler machines allowing for better temperature control. So I guess bigger is better after all!
We also examined the functionality of the E-61 group head and how the circular flow of this system is beneficial to the art of brewing espresso with consistent temperatures. When examining the PID, (Proportional-Integral-Differential), controller of this machine, we looked specifically at how the solid state relay plays an important role in the temperature stability process by sending pulsating electrical currents to the heating element allowing for consistency. Whoa! I’m starting to sound like one of them now. I may not be a true tech geek but after today’s lesson, I have become a lot closer with my new understanding of how these machines function. Beam me up Scotty!