# Londinium 1 temperature profiles



## Stevebee (Jul 21, 2015)

I recently bought an original L1 on the forum. Unfortunately moving it from place to place resulted in the OPV valve giving up and restricting water getting to the boiler. Reiss supplied a new trombone pipe which solved the issue although not before I had removed the boiler, heat exchange pipe and carried out a full descale, bending two pipes in the process. Considering I'm not the original owner, Reiss's help in supplying replacement pipes and getting running again was absolutely amazing.

Decided to do some temperature testing to see what pstat setting I want and what effect it has. Had one thermocouple on the group at 9 o'clock half way up the group. The other was in the portafilter, a few mm below the surface when filled with 16g of coffee. The way the lever works meant that filling with coffee was the only practical way for me to restrict the flow of water during a normal shot. Did 5 shots back to back. The red line is group temp, the blue the portafilter probe. All had 16g in, 32g to 34g out in 30s

Shot 1 : Cold portafilter, 8s preinfusion

Shot 2 : 8s preinfusion, flush just before shot

Shot 3 : 18s preinfusion

Shot 4 : 8s preinfusion

Shot 5 : 18s preinfusion

Once finished the group stabilised at 86.4c ongoing.

Findings (on a very small sample)

1. To reduced brew temp by a couple of degrees use a cold portafilter.

2. A flush before the shot raises the group temp which in turn increases brew temp by 1c - 2 c

3. Didn't see much impact on temp between 8s and 18s preinfusion - I thought the longer PI would lower brew temp.

4. When I reduced pstat to 1.2bar, the group temp lowered by about 1c which should impact brew temp.

The shots look longer than 32s but I left the portafilter in a wee bit to avoid the sneeze before removing.

Happy that consectutive shots were temp stable although I wouldn't flush post shot if you are doing one after the other as group temp may creep up. With more time between shots I would as the group has time to regain its equilibrium.

Both the group and shot temp look to be stable and repeatable and the shots are tasting very good as long as I dose lower.

A basket that I can fill 18g on a Vesuvius was nearer to 16g on the L1. Otherwise the coffee would hit the screen.

Will do a similar exercise on the Vesuvius as I know the group on that is stable from the group thermometer and as I have been using it longer know it produces some great shots with a lever type profile time and time again.

So far, despite the initial technical issues, am more than happy with the coffee the L1 is producing. Just resisting the lure of 3 bar preinfusion on the LR!


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## mathof (Mar 24, 2012)

Those are very interesting results. I've been thinking of making similar measurements with my L1, but I'm unsure how to mount the thermocouple in the basket. Did you drill a hole in the basket or just thread a thin wire tc over the edge of the pf?


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## Stevebee (Jul 21, 2015)

Drilled a hole through the bottom of a ridged basket I didnt use. Also secured with a thin screw and nut as pressure could blow the thermocouple out. The thermocouple then is about 2 or 3mm below the surface when filled with 16g. With a bit of grind tweaking on the Niche got the pour act 30s, for 32g. The thermocouple is a fast response one for use in liquids so water cant creep up the sheath. An Amprobe TMD-56 does the measurements.


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## Stevebee (Jul 21, 2015)

This method gives the temp in the coffee during extraction, which is most practical with a lever.

When I wanted the temp of the water dumping from the piston, I reduced the coffee so the probe was just above the coffee, tightened the grind to compensate the faster flow due to less coffee. Was still a bit fast and not perfect but ok for the purpose I wanted.


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## mathof (Mar 24, 2012)

I presume the temperature of the brew water "dumping from the piston" was higher than found inside the puck, but did it decrease in line with the same profile as when measured inside the puck?



Stevebee said:


> This method gives the temp in the coffee during extraction, which is most practical with a lever.
> 
> When I wanted the temp of the water dumping from the piston, I reduced the coffee so the probe was just above the coffee, tightened the grind to compensate the faster flow due to less coffee. Was still a bit fast and not perfect but ok for the purpose I wanted.


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## Stevebee (Jul 21, 2015)

mathof said:


> I presume the temperature of the brew water "dumping from the piston" was higher than found inside the puck, but did it decrease in line with the same profile as when measured inside the puck?


From what I recall yes it was higher and then declined. To be honest I didn't log the details on Artisan as I was focussing on the puck temp. When I get a chance I'll connect it up and hopefully show the graph with the puck profiles as background.


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## mathof (Mar 24, 2012)

Thanks. I intend to record my measurements in Artisan too, and I'll post them for comparison. One other thing, I can't quite picture your thermocouple/basket arrangement. I've tried something similar with a normal K-type probe and lead, but it did blow out when the spring engaged. If you could post a picture of your screw and nut arrangement, that would be very helpful.


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## Stevebee (Jul 21, 2015)

Will do tomorrow. It's basically a long thing fine pitch screw with the nut underneath. The thermocouple goes through the same hole as I widened it a bit. The top of the screw keeps the thermocouple in place. It didn't need it but I've added some plumbers putty to block any gaps where the screw goes as I wasn't going to slow the flow with coffee (was going to be duck tape with a pin prick) but coffee works well so didnt use the tape. Might remove the putty thinking about it as it will be a neater finish.


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## NickR (Jul 1, 2011)

Many thanks for your post Steve. Like everyone else I've not been able to measure in basket temps. I hope you get your LR soon, a comparison would be fascinating.


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## Stevebee (Jul 21, 2015)

NickR said:


> Many thanks for your post Steve. Like everyone else I've not been able to measure in basket temps. I hope you get your LR soon, a comparison would be fascinating.


Not sure I can justify the LR in addition the the L1, Vesuvius and Ponte Vecchio Lusso! Haven't the space for one thing.


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## ATZ (Aug 4, 2017)

@Stevebee I'm the owner of a Profitec Pro800 as I missed out on the L1 you got from the forum. I'm currently running my PID at 121C for boiler temp, which gives me 1.1bar of boiler pressure., may be useful as a comparison for you regards starting water temp, although it does have a 3.5 liter boiler.

One thing I've found is a difficulty in dialing shots in, so I've also ended up dosing a lower amount in the basket to get a decent shot.


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## Stevebee (Jul 21, 2015)

ATZ said:


> One thing I've found is a difficulty in dialing shots in, so I've also ended up dosing a lower amount in the basket to get a decent shot.


I've posted separately on this very issue. In an 18g VST I dose 18g on the Vesuvius with no screen impression. Using a 5 pence piece there is a slight impression but half the coin is showing.

On the L1 the screen sits closer to the basket. 16g leaves virtually none of the coin showing so on the coffee I'm using (medium roast) probably 15.5g would be the same distance away as on the V. So I'm ignoring the basket rating as if I filled 18g in the 18g VST on the L1 the screen pushes down on the coffee with absolutely zero headspace. I know it's dependant on the coffee as a light roast will be different.

Also, the best looking and tasting shots have come when I get a flow of 1g per second once the flow starts. I've tried tightening the grind so 32g comes in 55 to 60 secs but the taste and crema are not the same. I always tamp light, just to level the puck.

The grind for my best flow on these beans is 23 on my Niche. The Niche grind on my lever profile on the Vesuvius is 21.

However, if I reduce the V preinfusion to 7s from 14s the grind is the same. The grind difference is the same on the E10 but as I only use it with a full hopper at weekends I'm more familiar with the Niche settings for different beans.


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## Stevebee (Jul 21, 2015)

ATZ said:


> I'm currently running my PID at 121C for boiler temp, which gives me 1.1bar of boiler pressure.


 I've turned my pressure down to 1.2 from 1.3 as a result of the test. It was the first time I've left the L1 on all day and found the group temp did creep up over time from 86 to 88. Hasn't shown any creep since I reduced it - not sure why. Will probaly run the same sequence of shots at this lower pressure and compare. Do like the taste at 1.2


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## ATZ (Aug 4, 2017)

Stevebee said:


> I've posted separately on this very issue. In an 18g VST I dose 18g on the Vesuvius with no screen impression. Using a 5 pence piece there is a slight impression but half the coin is showing.
> 
> On the L1 the screen sits closer to the basket. 16g leaves virtually none of the coin showing so on the coffee I'm using (medium roast) probably 15.5g would be the same distance away as on the V. So I'm ignoring the basket rating as if I filled 18g in the 18g VST on the L1 the screen pushes down on the coffee with absolutely zero headspace. I know it's dependant on the coffee as a light roast will be different.
> 
> ...


 @Stevebee I'm reliably informed that swapping the usual screen for an IMS or Cafelat one gives more headroom on these groupheads - I'm considering getting the modern lever kit that Cafelat sell, which includes 3 silicone piston seals and a new screen.

I'm not sure if my Niche is calibrated differently but I'm at closer to 8 - 12 range depending on bean.


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## Stevebee (Jul 21, 2015)

ATZ said:


> @Stevebee I'm reliably informed that swapping the usual screen for an IMS or Cafelat one gives more headroom on these groupheads - I'm considering getting the modern lever kit that Cafelat sell, which includes 3 silicone piston seals and a new screen.
> 
> I'm not sure if my Niche is calibrated differently but I'm at closer to 8 - 12 range depending on bean.


 @ATZ I've got the IMS200, the Cafelet version of the 200, the IMS35 from Londinium and Kees van Westen.

The 200 give slightly more headroom as they are flatter. The Cafelet 200 has moe centre holes then the std 200. The Londinium 35 and KVdW are similar with mesh and similar hole pattern of the reverse.

The Niche calibration depends on what is finger tight and the roast / bean. My Decaf is at 14 or 15


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## ATZ (Aug 4, 2017)

Stevebee said:


> @ATZ I've got the IMS200, the Cafelet version of the 200, the IMS35 from Londinium and Kees van Westen.
> 
> The 200 give slightly more headroom as they are flatter. The Cafelet 200 has moe centre holes then the std 200. The Londinium 35 and KVdW are similar with mesh and similar hole pattern of the reverse.
> 
> ...


Noticed any difference between these?


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## Stevebee (Jul 21, 2015)

The KVdW is on the Vesuvius. I'm undecided between the Cafelet and Londinium 35 - currently the Londinium 35 is on.

Had one issue when I regreased the piston after changing seals. Did the 30 pulls and wiped excess grease at bottom of piston as per instructions. I must have used more grease as the screen got really clogged which meant most water rushing down the centre, breaking the puck and bad extraction. The silicone grease is a real pain to remove so avoid it in the first place. I won't replace the shower screen next time until I'm sure the excess has been removed.


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