Wednesday, October 15, 2014

Brew Pressure Gauges on Espresso Machines

Today, we figured out why espresso machine manufacturers were delaying the installation of brew pressure gauges on home model espresso machines. They wanted less support calls and less inquiries.

The brew pressure gauge is a wonderful tool for diagnosis of a failing pump/blockage internally or for when a customer has a an issue with the espresso extraction. However, it is not a requirement to pull a fantastic espresso extraction.

More specifically, the brew presure gauge will indicate if you need to create more resistance in the puck - the coffee that is in the filter basket. The resistance is created by the amount of ground coffee is in the basket, the grind fineness, and the tamping pressure. When the gauge's pressure is too low, one needs to increase the amount of ground coffee, the tamping pressure, and/or the fineness of the grinds (finer). If the brew pressure is too high, then these need to be lessened.

Without a brew pressure gauge, it is easy. Just look at the pour and time the extraction. Yes, a wasted show, but it would have been wasted anyway even with a brew pressure gauge on the espresso machine.

So, whats the problem with the gauge? The problem is that users read the gauge when not making espresso. Inquiries come in that that the gauge does not go to zero when the espresso machine is at standstill or there is pressure showing when the machine is powered off.

The brew pressure gauge should only be viewed when extracting espresso! It has no meaning when the machine is idle. On a tank model machine, it can measure the pressure of the water internally in the pipe between the pump and grouphead or even somewhere else in the line. Therefore, it is possible to have a reading on the gauge when the espresso machine is idle or powered off. On most direct plumbed espresso machines (those hooked up directly to the water line), it can show the water line pressure.

The other reason for the delay was that limescale can clog the capilary tube that runs from the connection to the rear of the brew pressure gauge. This is just another part that can go faulty.

So, many espresso machine manufacturers were smart to delay the implementation of the brew pressure gauge on home model espresso machines. However, competition in the market has made it more widespread across machines. Hence, the number of inquiries about the reading of the gauge while the espresso machine is idle has also increased. Therefore, please spread the word! And, visit!

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