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.
What makes EP Sproline Precision Group Screens so different?
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 be 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 crema 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.
For best results please follow these tips:
- The particular grind size for use with these screens is typically larger than that of standard group screens. Using a standard grind size will result in plugging of the screens precision holes.
- Sharp grinder burrs are a must for quality coffee and will result in consistent extractions. Worn burrs will result in too many fine particles, which tend to clog the screens and add to sour, over-extracted flavours in the extraction process.
- A brief wipe down of the screen should be added to your machine maintenance every few shots. Just as you would wipe the portafilter basket dry, the screen should be wiped after use to remove grounds from the prior shot.
- These screens fit all La Marzocco, Synesso, Slayer and Simonelli products
Made in Japan.