Out of the box pump pressure - Rocket Mozzafiato

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Fitzspresso
Posts: 2
Joined: 3 months ago

#1: Post by Fitzspresso »

Hey Everybody! My first post! I own several machines - and have been brewing espresso for 39 years - but I am very much an amateur. I live in the mountains of BC Canada and technical support is hard to come by.

I just purchased a new Rocket Mozzafiato V (for vibrating pump). When brewing a shot, the pump pressure is indicating only 7.8 - 8 bar. With a blind filter installed it only indicates 8.8 bar - with a fluctuation of about .2 bar. Isn't this low for a factory set pressure? Your thoughts please - should I adjust it higher - to say 10-10.5 bar?

The machine is pulling good shots. The adjustment is not difficult but I am hesitant to do it myself for fear of voiding the warranty on my new machine. The case must be disassembled and one of the OPV valves adjusted. The dealer has been very slow to respond to my query. Purchased from an online retailer.

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Jeff
Team HB
Posts: 6881
Joined: 19 years ago

#2: Post by Jeff »

Welcome to H-B

There are a couple things going on. First, 9 bars is a number somebody made up half a century ago for a completely different era of pump-driven machines and, more importantly coffees and grinders. Even 10-20 years ago, many of us were finding more enjoyable shots with blind pressures closer to 8 than 9. People pulling light roasts ("filter" coffee as espresso) are now often pulling them at 5 bars or lower. Many have also found that pressures above about 8 bars in the basket (probably around 9 bars into a blind basket) produce less enjoyable espresso than lower pressures.

I don't know that there is much point in watching the gauge during the shot. Well, at least for a few years until you think it is worthwhile to see if your pump is failing. Vibe pumps tend to last 3-10 years somewhere and often get weak before they fail. While they can manage 8 or 9 bars against a blind basket with no flow, they can't keep up as soon as there is flow.

You can tell if your grind is reasonable by judging the apparent thickness of the liquid and how fast it is flowing out.

Fitzspresso (original poster)
Posts: 2
Joined: 3 months ago

#3: Post by Fitzspresso (original poster) »

Good stuff. Thank you for taking the time to consider my query!