A Machine with More Than One Brew Boiler
In the 1920s, machines with more than one boiler began to appear on the market. Guido Snider’s electrically powered machine, shown in the photo above, featured two brew boilers and a separate steam boiler. The brew water was heated as it passed through the small, round boilers on the left and the right. The boiler in the middle produced steam, which was stored in the globe at the top of the machine to create, almost literally, a head of steam.
The First PID Controlled Multi Boiler
2001 was a big year for coffee innovations. The same year that Andy Schecter installed a PID in his home espresso machine for the first time, newly founded Dalla Corte went one step further. In its first year of operation, Brother and sister Paolo and Elsa Dalla Corte together with their father Bruno, founded the Dalla Corte company in Milan, Italy. They began to produce a machine called the Evolution, featuring small boilers above each group head. Each boiler was connected to its own PID controller. This advance allowed baristas to set each boiler to a different temperature, should they decide to brew in a different way or with a different coffee on each group. It allowed for more precise control of the brewing temperature whilst also making it easier to change the temperature.
Here Paolo Dalla Corte explains his family’s motivations for building a PID controlled multi boiler machine (see lesson 4.05)
‘We noticed that different local markets were facing the same issues: following an evolution of coffee, the limitations of machines with traditional technology (with thermosiphonic circulation) led both my father and I to re-think a new operating technology to overcome these limits. After carrying out tests on traditional machines to change the temperature-boiler and temperature-groups ratios — the temperature of the latter being a consequence of the boiler temperature — we started considering the idea of disconnecting the brewing units from the main boiler.