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Lelit Mara and pre-infusion


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I'm coming back to this as i don't quite understand it. I have a fantastic Lelit Mara which has a pre-infusion by lifting the lever 45 degrees. I have yet to use this function as it appears that the machine does it's own pre-infusion when you lift the lever fully (it appears to linger around 3 bars for a few seconds before ramping up to 9bar) though I can't guarantee this is what's happening.

I'm just wondering am I right in this? Should I be doing my own pre-infusion for a few seconds before lifting the lever fully? And if so, how does that impact 1. the grind size and 2. the length of time for brewing? e.g. is it 28-30 seconds from lifting the lever fully or 28-30 seconds from the start of the pre-infusion? 

Thanks!

Paul

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The mid position on the E61 is useless. It allows water into the group, but not activating the pump. What you get is some dribble from the siphon loop. Nothing else.

unless... your machine is plumbed in. In which case you can pre infuse with line pressure.

 

E61 has a pre-infusion chamber/valve which opens around 4 bar (depends on the strength of the spring). thats what you are seeing, besides the MaraX pump ramps up nice and slowly.

Edited by MediumRoastSteam

Current: Lelit Elizabeth / Niche Zero / VST baskets / Distilled water + 100mg NaCO3/L

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Also at: CoffeeTime Forum & Niche Zero Owners Group

 

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  • 1 month later...
On 02/09/2020 at 13:36, MediumRoastSteam said:

The mid position on the E61 is useless. It allows water into the group, but not activating the pump. What you get is some dribble from the siphon loop. Nothing else.

unless... your machine is plumbed in. In which case you can pre infuse with line pressure.

 

E61 has a pre-infusion chamber/valve which opens around 4 bar (depends on the strength of the spring). thats what you are seeing, besides the MaraX pump ramps up nice and slowly.

So, timing of shots starts at 4 bar of pressure, is that what you are saying here?

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10 minutes ago, skylark said:

So, timing of shots starts at 4 bar of pressure, is that what you are saying here?

With a vibe pump, flow rates are much lower and everything is far more gentle and civilised. So ideally start timing from the moment you lift the lever, as that's a consistent point you can always use.

===========

The 4 bar thing is just the pressure the preinfusion chamber opens at. It's capacity is around 10-12ml and at 4 bar pump pressure it takes a second or so to fill. This is the brief pause at 3 or 4 bar you might see in the pressure ramp when pulling a shot. It is the"pre-infusion" phase of the E61.

It was originally done to soften the massive hit of a commercial rotary pump (not the smaller motors and rotary pump heads we have on prosumer stuff). The commercial pumps produce a massive flow into the group. The 0.7mm jet (Gicluer) softens that flow a little but the preinfusion chamber helps prevent this pressure slamming down on the puck.

 

Edited by DavecUK
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Just now, DavecUK said:

With a vibe pump, flow rates are much lower and everything is far more gentle and civilised. So ideally start timing from the moment you lift the lever, as that's a consistent point you can always use.

===========

The 4 bar thing is just the pressure the preinfusion chamber opens at. It's capacity is around 10-12ml and at 4 bar pump pressure it takes a second or so to fill. This is the brief pause at 3 or 4 bar you might see in the pressure ramp when pulling a shot. It is the"pre-infusion" phase of the E61.

It was originally done to soften the massive hit of a commercial rotary pump (not the smaller motors and rotary pump heads we have on prosumer stuff). The commercial pumps produce a massive flow into the group. The 0.7mm jet (Gicluer) softens that flow a little but the preinfusion chamber helps prevent this pressure slamming down on the puck.

 

Thanks @DavecUK... i understand. My shots are not hitting the cup till around the 10sec mark progressing on to complete, lets say 18/36 in around 35 secs. Two questions, that 10sec first drip is something i cant seem to change despite grinding coarser, sound about right or not and that 35 secs completed shot has never produced anything drinkable for me, maybe i've just not got the right taste buds for espresso!

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2 minutes ago, skylark said:

Thanks @DavecUK... i understand. My shots are not hitting the cup till around the 10sec mark progressing on to complete, lets say 18/36 in around 35 secs. Two questions, that 10sec first drip is something i cant seem to change despite grinding coarser, sound about right or not and that 35 secs completed shot has never produced anything drinkable for me, maybe i've just not got the right taste buds for espresso!

You probably could change that 8-10s but you would be so coarse with an 18g shot, it would then be too fast. The vibe pump water output falls off sharply as pressure rises, so at 9 or 10 bar in a perfect world it's around 240ml per minute. So that's around 40ml-50ml in 10 seconds (because the shot goes through a low to high pressure phase). Spookily enough this is about the amount required to fill the headspace in the group and saturate a coffee puck....hence you see the drips at around 8-10 seconds.

Without me going back over the other posts re the difficulties you are having getting a good shot out of the Marax...if you were getting good espresso out of the previous machine, then there is not really a reason why you can't out of MaraX. Theres nothing particularly unusual about the machine beyond the lack of a need to flush and the quiet pump that would affect the ability to get decent espresso over any other HX machine.

I suspect the answer may lie areas other than preinfusion though. Just some things to think about and try...assuming all things being equal.

  • The other machine may have had a much hotter/colder brew temp and your taste got used to this with the coffees you like - Try playing around with MaraX temps, try 0 and even flush down 1C to see if this helps. Or try III and see if it's better and you can even bump up by lifting the lever and waiting 40 seconds before pulling the shot etc..
  • The longer the brew time in general the higher the extraction and the bitterness can increase. Try shots at 25s, thru to 35s
  • If shots are sour - Don't use the energy saving function on MaraX, make sure it's always warmed up fully (just cos the light stops flashing, absolutely doesn't mean it's ready)
  • 1:2 may not be right for that coffee - Experiment with ratios

If you have a member near you, it would be pretty useful to get together once this Covid lockdown business is behind us and get a second set of eyes on things.

 

 

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Thanks ... i'll give those suggestions a try, coffee i'm currently using is a CoffeeCompass Malabar Hit, medium/dark roast and i've tried it on temps 0 & 1.  My problems i feel revolve around the timing at 1:2, those 10secs to first drip i've tinkered with a lot and still do not get a drinkable shot. Dont use energy saving and machine always fully warmed up although maybe too warm as i'm a slow brewer as mentioned in other posts and feel that i'm possibly not at optimum temps especiatlly when i pull that second shot in the morning. Thanks for your time, i'll keep at it!

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Ah...Monsoon Malabar, one of the coffees I like to get now and again. I tend to roast it medium...sort of cadburys milk chocolate I guess and you do have to be careful with brew temps...It really prefers (at my roast level) a low brew temp. If I go over a little on the roast, it can get quite bitter.

I keep meaning to nip over to Traders Coffee and get a pillowcase full as a whole 50Kg sack is just too much....

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25 minutes ago, skylark said:

Thanks ... i'll give those suggestions a try, coffee i'm currently using is a CoffeeCompass Malabar Hit, medium/dark roast and i've tried it on temps 0 & 1.  My problems i feel revolve around the timing at 1:2, those 10secs to first drip i've tinkered with a lot and still do not get a drinkable shot. Dont use energy saving and machine always fully warmed up although maybe too warm as i'm a slow brewer as mentioned in other posts and feel that i'm possibly not at optimum temps especiatlly when i pull that second shot in the morning. Thanks for your time, i'll keep at it!

Why are you trying to make the coffee flow before 10 seconds? In what way are the shots not drinkable? 

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