# Lower pressure shots



## Wobin19 (Mar 19, 2013)

I have reduced the pump pressure on the R58 to 7!bar on the gauge. I was struggling with the last LSOL as it aged and was not getting tasting notes other were discussing. I think my machine had adjusted itself over time to a too high pressure of over 10 on the gauge. The locknut was loose, perhaps caused by vibration.

Also sometimes I got the infamous squeak from the group as pressure began building after the initial auto pre infusion. No sign of that now.

Anyhow without much grind adjustment I am getting really nice extractions and different flavours more like what others are describing. I am probably late to the party on this low pressure extraction thing. Any other Rocket owners reduced the rotary pump pressure? Not tried other coffees like this yet.


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## PeterL (Aug 5, 2015)

Mine is working at 10.5 bar, never thought about it, what's the adjustment process?


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## Wobin19 (Mar 19, 2013)

PeterL said:


> Mine is working at 10.5 bar, never thought about it, what's the adjustment process?


Underneath the machine there is an adjustment nut and a locknut. Using an open ended spanner you can adjust. Anti-Clockwise decreases pump pressure. Not saying it's not right at 10.5 but it's just yet another parameter to play with!


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## Jon (Dec 3, 2010)

I think @Scotford is/was rocking 5 bar on his commercial?


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## Phobic (Aug 17, 2016)

don't know anything about rockets but give 6 bar a try if you can, that seems to be what a lot of people are running generally


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## Wobin19 (Mar 19, 2013)

Phobic said:


> don't know anything about rockets but give 6 bar a try if you can, that seems to be what a lot of people are running generally


Ok will do, thanks!


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## Stanic (Dec 12, 2015)

Here and here is some reading on low pressure espresso extraction


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## Scotford (Apr 24, 2014)

Jon said:


> I think @Scotford is/was rocking 5 bar on his commercial?


Sure have been. 5 bar is generally the lowest I'll go these days and 7 the highest. All depends on the coffee being run through it. Currently sat nicely at 6bar static and 92.5°c for a 60/40 natural Nicaraguan and washed Rwandan blend.

I've actually found that below 5bar you get too low a flow rate for the workflow I've employed. Can't be having 40sec shots on a 600+ shot service.


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## fluffles (Sep 4, 2012)

Scotford said:


> Sure have been. 5 bar is generally the lowest I'll go these days and 7 the highest. All depends on the coffee being run through it. Currently sat nicely at 6bar static and 92.5°c for a 60/40 natural Nicaraguan and washed Rwandan blend.
> 
> I've actually found that below 5bar you get too low a flow rate for the workflow I've employed. Can't be having 40sec shots on a 600+ shot service.


I'm interested to know what determines the pressure you use for a given coffee - e.g. what would make you think "ah, I need to reduce/increase the pressure for this coffee" (in preference to fiddling with grind, temperature, etc)


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## Scotford (Apr 24, 2014)

fluffles said:


> I'm interested to know what determines the pressure you use for a given coffee - e.g. what would make you think "ah, I need to reduce/increase the pressure for this coffee" (in preference to fiddling with grind, temperature, etc)


It's mainly dial in a recipe at a certain dose, yield, time, temp and then spend a day at a different pressure and see what gives the most consistently delicious shots due to blind tasting and refracting.


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## 387ena (Jun 28, 2017)

Hello everyone

I have one question for more experienced.

I have Rocket Giotto evo v2 and the dilemma is about the pressure in the boiler.

At the moment the heater dropped to 0.9bar and went to 1.1bar.

Pump pressure is 9bar.

The coffee I get is tasty but the foam is not rich enough.

Can this be the reason for the weak foam?

What are your experiences.


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