New User - Lever Catches at 11o'clock? Low Volume

Paul Halliday

Hi all, new user question please

I've been playing with my new L1 for around 2 weeks. It's a learning curve. I'm having issues with the lever catching very high and low shot volume. My routine is:

Dosing 18g in an 18g VST basket. Compak grinder, dialled to 14. Fresh beans from Artisan Roast in Edinburgh roasted 18 Oct (sumatran). Short flush. Just over 1 bar pressure when lever pulled. Count to 10 seconds pre infusion & release.

Shot sits on Acacia scale. Drops form after a few seconds pre infusion but on release its over 11 o'clock on the dial when the lever catches. Nice flow but shot stops at 25-26g in the cup after 20-25 seconds.

I've read that I should be able to get a 2:1 ratio coffee out to coffee in. So I was expecting 36-40g in the cup and 25-30 flow time. I've been up and down the grind dial from 9-20, tamp hard tamp soft but I can never get the lever to catch lower than after 11 and consequent short flow time and never got above 28g in the cup.

I'm at a loss and wasting coffee. Can anyone help me please with some advice or tips

P
G

Frans Goddijn

18g in and 25g out in about 25s sounds perfect to me. That's what I aim for mostly and I let the rest of the fluids go into the drip tray.

Do you use the new custom seals?

Have you tried a slightly higher boiler pressure?

Do you release the lever *after* you see the first coffee droplets begin to appear all over the underside of the filter basket?

Paul Halliday

Frans, many thanks for taking time to reply. I know taking knowledge from books is no substitute for experience but 18g in 25g out is 1:33. I was under impression 1:5 or 1:2 was the sweet spot target. It just "feels" with the lever catching so high there is barely enough time / or water to get over 26g. The 26g is wringing every drop not pulling the shot. If I followed your You Tube videos ( excellent by the way) technique I'd get 21g in 19-20s.

I don't release as soon as drops appear. Reading the forums I followed Reiss recommendation for a longer 10s-12s pre infusion. The drops stop after 5s, I release after 10 & guide lever up to 11 where it catches. All that "action" is in the 25s timeframe.

The machine is new & I've not enough confidence to fiddle with pressure but the gague shows just over 1 bar.

As the machine is new I didn't think I needed to replace seals as yet? I was sure there was enough grease on when I fitted. Would it be too much Loxeal causing the lever to catch very high?

Frans Goddijn

Paul Halliday post=11949 wrote: The machine is new & I've not enough confidence to fiddle with pressure but the gague shows just over 1 bar.

It's not a hard exercise to try 1.3 bar for instance, very easy actually, just if you're careful you want to pull the power plug before sticking the screwdriver into the pressostat.

About the numbers you mention. The following with a smile: I assume the coffee is excellent and one drinks coffee, not numbers, so if you're fine, that's excellent! If you want to try a slightly higher shot volume, the slightly higher pressure would get you there already.

Robert Hall

Paul,
You need to find out if you have the new custom seals...I presume not. I got my L1 about a month ago, and started have problems with the lever engaging too high after 2 weeks. The new custom seals just came out and should fix the issue...I just installed mine tonight. Fairly easy task if you follow the video directions!
Rob

Gilles

Hi Paul,
I see that you already increased the PI up to 12"
Did you try grinding slightly finer, increasing step by step? with a soft tamping (more nutating style?)
cheers

Paul Halliday

Hi Gilles
Yes I've taken the grind down to 9 & as high as 25 on Compak. 14 seems to be the optimal. I've also dosed 16g to 20g in an 18g VST and pre-infused 8-12 secs in various combinations. Per the Acacia usually I get 21g to max 26g in 20-26 secs incl pre infusion before release & squeezing last drop. Lever always catches at past 11 so it seems to me in the time to vertical only 26g max ever has time to come thru. Breaking down 2g comes out in 10s then in remaining 12-15s after release I get 20-24g

Reiss has kindly sent me the new seals so I'll try & fit those as I'm told that will assist high catch issue. Seems a shame to cut off old seals after only a few weeks but if it resolves I'll be glad. I may be off beam thinking the high catch & consequent short time to vertical is the be all & end all of low volume but can't think of owt else to try

Reiss Gunson

the high performance seals will fix it paul.

Gilles

clearly, you tried out many things anyone could think about. Reiss is right (like for once )

I'd probably should do the same even I'm not troubled too much with the 11 o'clock because it's been the same since day one even after trying no many variation (qty, grind, pressure, PI,...)

cheers

Robert Hall

Gilles,
My original seals worked for 2 weeks and I got superb esppresso. Then I started getting the lever engaging high. Espresso went way down in quality. With new seals installed, back to superb espresso. For the machine to operate correctly, the lever needs to engage around 45 degrees.
Rob

Gilles

Thanks Rob, thiis is informative.
I always wondered why I should bother with this "around 7 degrees" lever since I don't need much in my Ristretto, thinking that since you can't adjust the water quantity it would just increase the amount of water going to waste after I get my cup OK
So it clearly had an impact on your extraction ?
thanks

Robert Hall

Gilles,
Absolutely! Its like night and day for me. I was really amazed at how good the espresso was when I first got the machine, and then after 2 weeks the seal started to fail, and there was an immediate change. If the lever engages higher I presume you are not getting the same pressure profile from the spring.
Rob

Gilles

Thanks Rob, appreciated.

Terra Banes

Do the custom seals mentioned apply to the older machine, the original londinium 1 model?

My lever engages very high up as well, but I have no idea whether the installed seals are the custom ones or a standard londinium set of seals. How does one distinguish?

Frans Goddijn

The general purpose seal on the market leaves a little 'wriggle room' in the width of the cutout that the seal is in. The custom Londinium seal is a perfect fit.

Where the lever 'grabs' is, assuming the seals are correct and undamaged, a result of the pre-infusion pressure.

In your model, if the boiler pressure is a little higher, the lever may grab a little lower.

If the puck has not preinfused completely, part of the lever spring action will be used to complete that preinfusion and the lever will grab a little later/higher.

Terra Banes

Hmmmm... another mystery then, as I preinfuse longer than most , so the puck is wet when extraction begins. Still, I’ve not noticed any difference at all in the spot where the lever grabs, with reference to preinfusion timing. There is very little space between where it grabs and where it stops, and that spot never appears to change. But flavour is good.:)

Frans Goddijn

As long as the shot is delicious, no reason to 'fix' anything ;-)

Reiss Gunson

the angle at which the lever grabs is a function of the pressure that the water is being pushed into the brew chamber when the piston comes down - you can see this illustrated very clearly in Frans' wireless dongle demonstration video that he posted a couple of weeks ago

with the L1(2012-16) you should be able to get the lever to grab at 45 degrees above horizontal, assuming that you have allowed the puck to saturate before releasing the lever

at low pre-infusion pressures if you release the lever too early (before the first drip) the bottom portion of the puck is still dry, so as the greater pressure from the piston forces down on the brew water which in turn 'collapses' into the dry portion of the puck, giving you a low brew volume & high lever grab

if you wait for the first drip to fall in the cup this is a reasonably reliable indicator that all areas of the puck are saturated, and so the brew water continues to migrate slowly through the puck at pre-infusion pressure and form a drip on the underside of the basket, which then falls into the cup

if you cant achieve a 45 degree lever grab with your L1(2012-16) boiler set to 1.3 bar or thereabouts (NB: LR, L1/2/3 boiler pressure should only ever be 1.0 bar) it is an indicator that your machine would benefit from the piston seals being changed

best

reiss.

Terra Banes

Well then, sounds like I will need to replace seals, as I am nowhere near a 45 degree angle. (I am meeting all other specs you have outlined, but still catch much higher. It was my understanding they had been replaced quite recently by the previous owner, but perhaps not.)

Out of relentless curiosity;) , does dose size affect the catch point at all?

Thank you for the details provided, most helpful!

Reiss Gunson

hi there

the higher you dose and the finer you grind and the harder you tamp the greater the probability that pre-infusion will not complete in a 'reasonable period of time' at the boiler pressure for the L1(2012-16) which is 1.3 bar (please note that the LR, L1/2/3 must all have a boiler pressure of 1 bar)

happily the completion of pre-infusion has a precise definition; when the puck is saturated

we know the puck is saturated when the system (in the case of the L1(2012-16) driven at boiler pressure) tries to add 1 more mL of water into the top of the puck and as liquids are non compressible 1mL of liquid must be forced out of the bottom of the puck in order to 'make room' for this one additional mL to the top of the puck as there is no longer any air spaces left anywhere in the puck

so to get back to your question, the larger the dose the more likely it is that unless you have waited for the first drop to fall that the puck will not be saturated (i.e. there will still be pockets of air in the puck) and so when you release the lever off the cam and the force with which the water is driven into the puck rises from 1.3 bar to say 8-9 bar from the expanding spring forcing down on the piston the brew water suddenly 'collapses' into any air spaces in the puck (sort of like what happens with a sink hole)

so if you have a saturated puck for 1 more mL to go into the puck 1mL must come out the bottom. when you release the lever with a saturated puck the lever grabs at the correct angle for the given level of pre-infusion pressure and the volume of brew water sitting above the puck before the load from the spring comes on is roughly equal to what your brew volume will be

however, lets say you had 40mL of brew water at 1.3 bar above the puck that was not saturated, but contained an area of dry coffee grounds in the puck with a volume of say 20mL. when the load of the spring pushes down on the brew water via the piston you are not going to get 40mL of espresso out the bottom of the portafilter. why? because 40mL of the brew water above the puck is going to 'disappear' when it hits the 20mL of dry coffee grounds, so you will only get 20mL of coffee out. when the brew water hits an area of dry coffee in the puck this is evidenced as a high grab on the lever as the downward movement of the piston is only arrested when all of the coffee below the brew water is saturated and the 1ml out for 1ml in rule is in force. it is only the resistance offered by the saturated coffee grounds against the additional brew water being forced downwards through the grounds that produces the espresso in your cup

hopefully this explanation has added clarity rather than confusion

if not, let me know and ill have another go at it

btw, feel free to use any brand of piston seals. they get their knickers in a bunch over on HB but im not troubled by it at all. the thin red silicone seals that bosco use on their machines are nice for extractions at boiler pressure but they won't enjoy LR pre-infusion pressures for too long. Cafelat seals are easy to fit and durable, but the produce a lot of drag; enough to significantly slow the rate of travel in the piston which im personally not keen on, but its entirely up to you; that is the beauty of these machines; there is a plentiful supply of parts worldwide and you can mix and match to meet your own preferences

best

reiss.

Terra Banes

Thanks for the description, Reiss. Really helps in my overall understanding, and I greatly appreciate your taking time to explain it.

I feel pretty confident the puck is well saturated. I usually use a 14 gram dose, & I grind a bit finer with this lower dose size, & follow with a quick londinium stir, level & light tamp ; I preinfuse until there are coffee beads appearing all across the screen, and wait for first 2 or 3 drops to fall into the cup.

I seem to get the best flavour by doing a few seconds preinfusion with the lever down, then follow with a bit longer preinfusion when the lever approaches the catch point (preinfusing up to 20 seconds overall). That last bit of preinfusion is where the coffee beads sweat across the screen and then emit a couple of drops; at that point, I let the lever travel on its own for the shot extraction. I stop the shot at 28 grams.


It may well be worth a try with another set of seals just to see if it does indeed change anything. (I’ll tackle that soon, assuming the holidays don’t delay me.