Lelit Mara X - Did you change the OPV pressure?

#1: Post by **shkob1** » December 29th, 2021, 8:11 pm

I'm curious to hear if Mara X owners have changed their brew pressure from the factory 10 bars to lower and whether you feel it made a difference?

Thanks!

#2: Post by **dfuller** » December 29th, 2021, 10:01 pm

As I got mine, it maxes out with a blind basket around 9.25 bars by the gauge. I can't say I've noticed any issues with the coffee...

#3: Post by **ShotClock** » December 29th, 2021, 11:49 pm

The pressure at the gauge is not the pressure at the puck. I added a group head pressure gauge to mine, and found that it was actually around 9 with a blind basket. I would recommend to leave in the stock configuration.

#4: Post by **rbax238** » December 30th, 2021, 10:50 am

Is this question being asked because of Hoffmann's rant: http://www.youtube.com/watch?v=e0kQ5WqjcU8

He insists that the rule is "9bars at the boiler, EIGHT bars at the brewhead.

As with many others, my machine was set by my vendor to 10bars at the boiler and 9bars at the brewhead (I have a brewhead manometer and boiler gauge). I can adjust the brewhead pressure with the Flow Control and I find that "in general" lowering the pressure tends to lower the "brightness" (acidity?) of the shot. I've been doing 8bar shots since seeing the video and I think I prefer them.

Now I find some people are advocating 6bar shots. Where will the madness end?

December 30th, 2021, 9:03 pm

Haha I think we're just bored and constantly looking for ways to get ourselves into this rabbit hole

#6: Post by **FourByFive** » December 30th, 2021, 9:43 pm

I'm thinking of adjusting my Appartamento to 1 bar. It'll be the most expensive pour-over system on the block.

#7: Post by **herbibore** » January 8th, 2022, 12:49 pm

I know this thread got derailed, but I was just about to post this same question in the MaraX thread so I thought I'd revive this one instead.

When I am running my new MaraX with the blind filter in, I get 10.5 bar on the machine and 11 bar at the head (see attached photos).

To me it sounds like the advice to "leave it factory calibrated" seems unwise given what I'm seeing, but I'm interested in if I'm not considering something.

Edit: I have the flow control kit pre-installed from Chris' Coffee, but I generally leave it wide open.

#8: Post by **ShotClock** » January 8th, 2022, 2:15 pm

Two things spring to mind here:

Pressure should not increase from the pump to the puck, your gh manometer may be inaccurate. I had the coffee sensor kit, and it showed around 9bar at the puck for 10 at the pump.

Leaving it wide open may well give higher flow than the regular setup, may be worth experimenting with this, even if you leave it at constant flow. Lower flow well give a more gradual ramp in pressure, which can help reduce channeling.

#9: Post by **herbibore** » January 8th, 2022, 4:25 pm

Very good point - I took the photos to "prove" that the grouphead manometer was higher because I thought it seemed odd, too. However, I contacted Chris' Coffee and they indicated that the higher pressure at the group was normal.

Assuming the built-in gauge on the face is correct, it's a hair over 10 bars at the pump, which seems to be what Lelit calibrates it for before it leaves the factory, if I'm not mistaken. If that's the case, I'm going to assume it's fine without adjustment - I haven't seen much discussion of changing it from that in the main MaraX thread.

#10: Post by **logjames** » January 8th, 2022, 8:10 pm

How accurate are those manometers? Is it safe to assume they are all perfectly calibrated from the factory? I suspect not. The built-in manometer is measuring the pressure of the brew circuit, not the pump. The resistance of the puck (i.e. how much water flows through the coffee in relation to how much water is being pumped) and/or OPV (how much water is being diverted from the brew circuit) which influences the brew circuit pressure and subsequently the reading on the manometer.