Variables that affect the catch point of the lever

Harold Bend

I have owned my L1 for about 6 months and am delighted with the aesthetics and function. I am getting excellent shots...most of the time. The one variable that I don't understand is what impacts the point at which the lever "catches" and starts pressurizing the puck. I weigh the coffee for each shot to the tenth of a gram, and feel I am fairly consistent with tamping pressure. I am using the same coffee, yet the lever seems to catch at different points. When it catches later, or higher, there is usually some water left in the puck, and extraction does not seem to be as good. I use a timer, and try to pull down on the lever to cock as evenly and consistently as possible, the same with the release after a timed 6 second pre-infusion. I apologize, I am sure this issue has been addressed before, but didn't find it with some simple searches. Thanks for giving me a hand. Harold

Reiss Gunson

hi harold

when you say 'high' do you mean higher than 45 degrees?

kind regards

reiss.

Harold Bend

Yes, It seems to be ideal around 45 degrees, but sometimes it is above that...hard to interpret the exact angle. I may get as much as a 10 degree...or slightly more variation.

Reiss Gunson

ill send you a set of our high performance seals. is the same address as the machine was sent to ok?

Robert Hall

Reiss,
Things are going very well with the L1 especially since I put the seals in some months back. My lever is catching at 45 degrees, but one thing I have noticed that I have not seen anyone mention, is that sometimes when I bring the lever up it catches nice and firm, and other times it catches very softly (hope this makes sense). Not 100% sure I notice major differences in the cup, but I think the shots are a bit better with a firm catch. Also, sometimes when I pull the lever down I hear a swoosh, and other times there is no noise at all. Not sure there is any difference in the cup.
I'm very meticulous with my technique: weigh the beans, use a Monolith, I time everything the same.
Any comments?
Loving the machine!
Rob

Reiss Gunson

hi robert!

i expect what you are experiencing is a reflection of the extent to which pre-infusion has completed when you release the lever

when pre-infusion is complete the piston is pushing the water into a saturated puck (minimal compression available), whereas if you have tamped a bit harder or ground a little finer using the same pre-infusion time may not allow pre-infusion to complete

if pre-infusion has not completed then the piston is pushing the water down into a puck with pockets of air and so you can sense that sponginess that you refer to

kind regards

reiss.

Reiss Gunson

a 'whoosh' suggests a small clearing flush of 50-60mL was not pulled after the last shot

most users would calibrate their technique so they release the lever when the first drop hits the bottom of the cup, often 10 seconds (the higher pre-infusion pressure of the LR/1/2/3 means you may shorten the PI to as little as 2-3 seconds for a traditional italian roast & dose of 14g and 2 bar PI, and 7 seconds PI would generally be enough for a light roast at 18g with 3 bar PI)

for the L1(2012-16) i would expect 8-12s to be a common PI duration

Robert Hall

Thanks, I'll check it out!
Rob

Harold Bend

Ahhh, I have slipped back to heaven! The new seals arrived quickly (although, the few days did seem like forever). Thanks to Reiss's video, changing the seals was a snap...although a note in packaging that the video is on the blog would have saved me a few moments of confusion. In any case, back to consistent, superb shots. Thanks all for comments, and Reiss, for your prompt attention.

Reiss Gunson

you'll be shocked at the difference our custom piston seals make i think.

Paul Molyneux

Hi, I've been reading the thread with great interest and glad that I'm not the only one experiencing the same set of issues. Where can I find the high performance seals? I suspect that this may be the problem that's causing my lever not to catch until about 15 degrees! That, and I tend to change the coffee beans quite regularly so have to dial in which often causes some shot issues. Thanks in advance! Paul

Reiss Gunson

hi paul

thank you for posting

we only offer the high performance seals now, and to the best of my knowledge they completely address the issue; you can find them here - https://londiniumespresso.com/store/espresso-machine-parts/one-londinium-custom-piston-seal

however, it is important to de-couple piston slip from operator error

the lever on any spring lever machine that undertakes pre-infusion at boiler pressure will catch high if you dose high and grind fine

how so? because when you only have boiler pressure to undertake pre-infusion it is very easy to turn the coffee puck into the 'mud brick house' effect

by this i mean that just as mud brick houses can easily hold out the rain, so it is true for a finely ground high dosed coffee puck with only boiler pressure to try and push the water into the puck - that is why we have moved to the higher pre-infusion architecture of the L1/2/3 for the LR - all the upside of a mains water pressure pre-infusion system without the need to plumb in! plug & play, thats why the LR is the ultimate lever

providing you dont re-create the mud brick house effect with your coffee puck (i.e. prevent complete pre-infusion from occurring), then you can expect the lever arm to grab at 45 degrees when complete pre-infusion has been achieved and the lever is released. indeed you will see exactly the same thing when you dial down the mains water pressure feeding an L1/2/3, i.e the lever grabs at 45 degrees when released (assuming complete pre-infusion has been achieved)

but for modern single origin speciality coffee you want 3.0-3.5 bar of pre-infusion pressure to cope with the larger dose and fine grind

i hope this helps

kind regards

reiss.

Paul Molyneux

Thanks for the swift response Reiss, much appreciated.

We try to be very consistent with our approach to dialling in our beans. We typically will go for around 17.5-18g of coffee and will adjust the grind accordingly, and as is usually the case will try some trial and error before we get to the right grind. We tamp lightly and take it from there.

One point that may confuse matters is that we read previous threads on this topic and tried to make the grind slightly coarser to aid pre-infusion. What we've noticed though is that the grind is sufficiently coarse that coffee starts 'dribbling' through during pre-infusion, and then upon release we are still only catching at about 15-20 degrees.

I'm hoping the seals will remedy this, but if there is any other advice you can share I'd be most grateful.

Cheers, Paul

Reiss Gunson

I’m afraid I have to suggest the distribution tool

It elevates the taste and consistency of your espresso significantly

I wouldn’t even bother making espresso without it

Because your distribution will be so much better you will be able to grind coarser without leakage at the start of preinfusion

The temptation if the distribution is poor, causing leaking almost as soon as the lever is pulled down, is to compensate by grinding too fine

Reiss

Paul Molyneux

Great - I just had a look at the distribution tool and will pop that in the basket. We do rotate the basket under the coffee grinder continuously to make sure an even distribution, but are of course willing to try anything.

I'm also still going to get the seals as well (I think these were last replaced over a year ago) - is there anything else we should consider to help out?

Tas, P

Reiss Gunson

I'm assuming you are weighing the dose with digital scales that can provide at least 0.1g accuracy?

the distribution tool is magic - i would place it head and shoulders above any other accessory

they dont just make a theoretical or academic difference, you just think 'wow' this is easy

reiss.

Paul Molyneux

Sounds like sorcery - looking forward to playing. We do use digital scales to 0.1g and have found that 18.0g has worked well in the past, but as always the pursuit of perfection is an endless one...