Now well into the...
fourth year of this humble coffee blog we're really starting to dig into the minutia of brewing, and in terms of espresso talking about shower screens is really getting into the weeds. Otherwise known as dispersion screens, these little discs of metal and mesh play a surprisingly vital role in the espresso brewing experience. They not only prevent mechanical breakdown by keeping large debris from finding its way into the discharge tube of your espresso machine, but they also play a role in providing a proper extraction.
If you ever take your screen off and look at the surface where it's bolted on, called the dispersion plate, you'll likely see some holes. Thats where the water is dispensed into your group, onto your puck, and eventually builds the pressure needed to push that sweet, sweet espresso out of the basket. The shower screen acts as not only a buffer for the water making its way to your coffee, but also ensuring that water is spread evenly (at least in an ideal world) across the entire surface of your puck.
Well, this is where today's video comes in. People have often asked me what sort of difference screens make, and honestly I didn't know. So I put two very different, but also pretty common shower screens to the test to see what, if any differences are made by solely switching the screen. So hit play on the video above, and let's espresso anatomy on!