# Matt perger, reduce pump pressure



## CoffeeChris (Dec 2, 2011)

Just reading matt pergers link about reducing pump pressure.... Is this possible on sage dual boiler machines?


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## NickdeBug (Jan 18, 2015)

yes - go into the pre-infusion setting and adjust time to 50s and pump pressure to 65%.

Go through your standard prep and run a shot. Watch the gauge and you are aiming for a steady 6bar. If too low go back and increase pump %, if too high reduce.

You will end up with longer pours so don't worry about time - just go by taste - or borrow a refractometer and check EY.

Above info all thanks to GaryD


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## CoffeeChris (Dec 2, 2011)

Thanks nick. Would you still do a pre infusion on top of this?


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## jlarkin (Apr 26, 2015)

You can't do preinfusion on top of it, as Sage DB only has one setting for preinfusion. You're using that option to run a lower bar shot instead. I imagine you'd still also want to consider changing your grind a little to get to the right bar Nick or @garydyke1? As in, if you run at 65% preinfusion and it's showing as 5 bar, would you increase percentage or grind a little finer and see where that put the %>?


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## Beanosaurus (Jun 4, 2014)

CoffeeChris said:


> Thanks nick. Would you still do a pre infusion on top of this?


What you are actually doing in terms of function is running an extended pre-infusion or rather the entire duration of the shot is being extracted at the set pre-infusion level but it never jumps to full-pressure.

You'll see the pressure steadily rise until it reaches it's peak, the pressure will remain briefly until full saturation of the puck has been achieved, from there on the pressure will decline as the majority of solids from the puck should have been extracted by then.

The pressure profile is very similar to how lever machines work.

My settings are -

Pre-infusion time: 60s. (Average 18g doses tend to be done in around 25s -35s.)

PP 'pressure-power': variable - this depends on the coffee I'm using and how soon after roasting;

if you have a naked portafilter and still seeing channeling despite good preparation then quite often a drop in pressure should an evenly saturated puck.

Personally, this is how I pull all of my shots on this machine. - The benefits besides more consistent extractions is that the vibration pump is significantly quieter!!!


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## jlarkin (Apr 26, 2015)

Beanosaurus said:


> My settings are -
> 
> Pre-infusion time: 60s. (Average 18g doses tend to be done in around 25s -35s.)
> 
> PP 'pressure-power': variable - this depends on the coffee I'm using and how soon after roasting;


What sort of pressure are you looking at generally / do you have a kind of expected window?


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## CoffeeChris (Dec 2, 2011)

Thanks all. Will try this. So basically ignore timing, go on taste? Seems to be in the 50 to 60sec would I be looking at the same output that I would normally get.


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## NickdeBug (Jan 18, 2015)

one word of warning - if you have set the "pre-infusion" for a particular duration, e.g. 60s, DON'T LET IT GO PAST THIS TIME! Otherwise the pump kicks up to full pressure and the end result is less than tasty.

It is a great way to get a more controlled pour, and as Beano says - it is also quieter!

Joe - adjusting grind/dose/pump% may all get the desired pressure (which I have been told is 6bar). I guess choosing which one to adjust is greatly aided by using a refractometer. Not something I would ever buy myself, but there are some friendly forum members who are happy to loan theirs for a bit.


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## Beanosaurus (Jun 4, 2014)

jlarkin said:


> What sort of pressure are you looking at generally / do you have a kind of expected window?


4-8 BAR, though every now and then I will run a shot at 9 BAR (albeit with pre-infusion







).


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## jlarkin (Apr 26, 2015)

NickdeBug said:


> one word of warning - if you have set the "pre-infusion" for a particular duration, e.g. 60s, DON'T LET IT GO PAST THIS TIME! Otherwise the pump kicks up to full pressure and the end result is less than tasty.
> 
> It is a great way to get a more controlled pour, and as Beano says - it is also quieter!
> 
> Joe - adjusting grind/dose/pump% may all get the desired pressure (which I have been told is 6bar). I guess choosing which one to adjust is greatly aided by using a refractometer. Not something I would ever buy myself, but there are some friendly forum members who are happy to loan theirs for a bit.


Thanks, interesting stuff this.

I have a refractometer so it would be nice to have something that it definitely helps with


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## CoffeeChris (Dec 2, 2011)

NickdeBug said:


> one word of warning - if you have set the "pre-infusion" for a particular duration, e.g. 60s, DON'T LET IT GO PAST THIS TIME! Otherwise the pump kicks up to full pressure and the end result is less than tasty.
> 
> It is a great way to get a more controlled pour, and as Beano says - it is also quieter!
> 
> Joe - adjusting grind/dose/pump% may all get the desired pressure (which I have been told is 6bar). I guess choosing which one to adjust is greatly aided by using a refractometer. Not something I would ever buy myself, but there are some friendly forum members who are happy to loan theirs for a bit.


Would holding down manual achieve the same, once I have set to 65% etc... What kind of output are you getting. Would I look to be getting same output as I do now?


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## Beanosaurus (Jun 4, 2014)

CoffeeChris said:


> ...Seems to be in the 50 to 60sec would I be looking at the same output that I would normally get.


Not entirely... Because while the reduction in pump pressure equates to less volume of water over a duration it is not entirely equivocal to a shot being slower to reach target yield (generally speaking).

The flow from the bottom of the basket is determined by how well the water is passing through contents,

so if we have areas in the coffee puck where no water is able to reach (as seen in shots with bad channeling) then that could result in a shot which takes an unusually long time to reach the desired output.

But with the chief aim of reducing pressure to achieve a more even extraction it means that while less water may be coming from the machine over the duration, the likeliness for channeling and back pressure is also reduced which should make for an unhindered flow of water through the bed of grounds.


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## garydyke1 (Mar 9, 2011)

If you could only get hold of preground coffee (perish the thought) you could dial in with the PP setting (and dose if needed )


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## NickdeBug (Jan 18, 2015)

Easier just to set the duration for longer than you should need - press Manual to start and again to stop.

As for output - stick with your brew ratio. If aiming for 1:2 then that's what you look for on the scales. I am running a little longer - approx. 1:2.3 as this seems to work better for my grinder and taste buds


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## garydyke1 (Mar 9, 2011)

CoffeeChris said:


> Would holding down manual achieve the same, once I have set to 65% etc... What kind of output are you getting. Would I look to be getting same output as I do now?


Yes it would , if you want to nurse it. Once you have a steady flow you could let that bad boy fly if the shot time is getting too silly (I've had >50 second super tasty shots with certain coffees)


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## CoffeeChris (Dec 2, 2011)

Thanks all. Looking forward to testing this out with my mazzer major


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## bronc (Dec 10, 2012)

Has anyone with a vibe pump machine tried this? I'm wondering whether the 1 bar difference between static and dynamic applies to lower pressure levels.


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## Bolta (May 11, 2014)

After reading Matt Perger's newsletter, I thought I would be clever and adjust the preinfusion perimeters to achieve 6 bar, only to discover that you folks have been doing this for ages.


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## CoffeeChris (Dec 2, 2011)

This is more difficult than I imagined it to be. Stuck at 3 bar at 65pp. Would that mean I need to go corser on the grinder?


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## Mrboots2u (May 10, 2013)

CoffeeChris said:


> This is more difficult than I imagined it to be. Stuck at 3 bar at 65pp. Would that mean I need to go corser on the grinder?


Depends what your recipe is......and what taste you want to achieve

Pull a shot > taste > adjust

You can go little coarse as a result of low pressure , try it and see


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## CoffeeChris (Dec 2, 2011)

Pulling 2:1 to start with. If I go much corser it pretty much flows out to quickly


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## Mrboots2u (May 10, 2013)

CoffeeChris said:


> Pulling 2:1 to start with. If I go much corser it pretty much flows out to quickly


presumably you mean 1:2 ?

Then go finer .. they are no fixed rules with this . What does too quickly mean as time isn't a variable you should be using to adjust your shots unless its totally askew ( like 15 seconds say ) ... work to the recipe , cut at desired weight, note time and adjust via taste ...


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## garydyke1 (Mar 9, 2011)

CoffeeChris said:


> This is more difficult than I imagined it to be. Stuck at 3 bar at 65pp. Would that mean I need to go corser on the grinder?


Go much finer . If it stlll only reaches a max of 3 bar then increase the PP to 67% and try again. Machine PPs seem to vary


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## CoffeeChris (Dec 2, 2011)

Sorry yes, 1:2. It was pouring at around 10secs so will try going much finer and increase pressure. Tasting quite sour too. Will keep trying. Thanks


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## Mrboots2u (May 10, 2013)

CoffeeChris said:


> Sorry yes, 1:2. It was pouring at around 10secs so will try going much finer and increase pressure. Tasting quite sour too. Will keep trying. Thanks


So you hit your brew ratio in 10 seconds


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## CoffeeChris (Dec 2, 2011)

Not quite, tried corser to see what would happen to bar. (which stayed on 3) will try a much finer grind.


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## CoffeeChris (Dec 2, 2011)

Sorted. Had to put my PP to 70 on my machine. Thanks all.


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## michaelg (Jul 25, 2013)

I'm mostly holding down manual on the 60s pre-infusion at 65% and when it starts to pour nicely through the middle, release to full pressure and finding I get about 1:2 out in 35s or thereabouts. Tastes pretty good!


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## urbanbumpkin (Jan 30, 2013)

Tried it this morning. Using the holding down the manual button. The grind setting was on the usual for espresso. 35g 38 sec shot the pressure as 3 bar.

Am I correct in thinking that to get the pressure at 6bar I need to go finer?

Tasted really nice I have to say.


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## SmithStCoffeeRoasters (Feb 23, 2016)

6bar is a guide not a rule it's system specific if it tastes great your there. The idea is lower pressure will extract more of the 'good stuff' but not all coffee brewing systems are the same


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## urbanbumpkin (Jan 30, 2013)

SmithStCoffeeRoasters said:


> 6bar is a guide not a rule it's system specific if it tastes great your there. The idea is lower pressure will extract more of the 'good stuff' but not all coffee brewing systems are the same


Thanks for the heads up. Totally agree going with taste, but you always strive for better







. 3 bar is a long way from 6 and was just trying to get it nearer that and see what it tasted like.

I thought a lower pressure shot would take longer than a 9 bar one. Which on 1st attempt it appears not to.


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## CoffeeChris (Dec 2, 2011)

I found this too. Was getting much taster shots below 40 seconds. Take a read of these articles https://strivefortone.com/2016/05/18/this-low-pressure-rehash/ and https://www.fcpcoffee.com/blog/post/marginal-gains-itx27s-all-in-the-mix


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## urbanbumpkin (Jan 30, 2013)

2nd attempt this morning. Set the Sage to 65 (previous attempt was at 55). Dial wound its way up to 6, stayed there for 10 seconds then slowly started to drop back down to 3-4 bar.

Shot tasted better than yesterday. 17.5=>40g in 30 secs. As I was holding the manual button down there was about a second of 9 bar at the end


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## urbanbumpkin (Jan 30, 2013)

Tried going finer with Sage set to 65 still. 18g=>37 in 39secs.

Pressure creeped up to 7 for about 10 secs then slowly dropped down about 3.5. Does anyone else get this?

Taste wise it was fantastic. A complete fruit burst without any over acidity.

I was using the LSOL Barn Berlin, it's one of the nicest spro shots I've pulled with these.


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## garydyke1 (Mar 9, 2011)

urbanbumpkin said:


> Tried going finer with Sage set to 65 still. 18g=>37 in 39secs.
> 
> Pressure creeped up to 7 for about 10 secs then slowly dropped down about 3.5. Does anyone else get this?
> 
> ...


Yep. Vibe pump : pressure and flow are inverse . As the flow increases the pressure will drop (like a lever machine)


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## urbanbumpkin (Jan 30, 2013)

garydyke1 said:


> Yep. Vibe pump : pressure and flow are inverse . As the flow increases the pressure will drop (like a lever machine)


Cheers Gary. Just out of interest, how come 9 Bar shots tend to remain steady at 9 bars on the Sage where as the lower pre infusions one sfluctuate?


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## jlarkin (Apr 26, 2015)

urbanbumpkin said:


> Cheers Gary. Just out of interest, how come 9 Bar shots tend to remain steady at 9 bars on the Sage where as the lower pre infusions one sfluctuate?


Mine don't, they often fluctuate sometimes going over 9 and then dropping towards the end


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## garydyke1 (Mar 9, 2011)

urbanbumpkin said:


> Cheers Gary. Just out of interest, how come 9 Bar shots tend to remain steady at 9 bars on the Sage where as the lower pre infusions one sfluctuate?


Fine migration?

EK shots are a different beast to Mazzer


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