La Marzocco & Synesso Coffee Machine Group Head Sproline Precision Shower Screen
The Sproline Precision Group Screen has been developed for the extraction of both coffee and tea. Its machined stainless steel retaining ring seals firmly to the dispersion block, creating a positive seal and therefore reducing the bypass of water during the extraction process.
A thick gauge stainless steel sheet with engineered precision hole size and placement delivers more consistent water flow from the group and over the top of the coffee puck surface. Please note that this screen should be used with the specific dispersion screw that has been designed to work in conjunction with it. This ensures an even delivery of water over the puck of coffee.
The materials and craftsmanship of these precision screens help to separate them from what is otherwise traditionally a very basic design.
In a word, Cavitation. In the instance of our screen project, we are utilizing the espresso machine pump in combination with the screen to develop Discharge Cavitation.
Discharge, or recirculation cavitation, is the result of changing pressure at the point of exit, or outlet. The outlet is not able to let all the liquid through as fast as it should, so the currents' different velocities create miniature changes in the uniform pressure.
Even such small variations are enough to create the ideal circumstances for cavitation. Now in the instance of submarines, this is not a great thing, but when used to extract coffee the results are a plus.
The drop in pressure after the group screen allows the ground coffee to absorb water at a faster rate during pre-infusion as well as the extraction cycle. This allows the puck of ground coffee to become more saturated than it would using a typical dispersion screen.
The pressure continues to build past the screens point of exit and into the portafilter basket and ground coffee. The resulting coffee is brewed in such a way that the resulting creama is typically free of large gas bubbles. Coffee that has become dated and stale can seem revived under this process, allowing for more working days with some coffees.
Made in Japan.
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