i think there are many ways to over extract. running it short will help, but it won't protect against a brew water temperature that is too high. shortening the pre-infusion time will also help by grinding more coarsely (reducing the time for the first drip to fall to 2s)
but i think you are much better to put the restrictor in because then you can keep the pre-infusion pressure much higher and in doing so you get a lot more body than you will achieve at boiler pressure pre-infusion settings (1.0-1.5 bar), which a lot of people enjoy in a dark roast.
I actually ordered the restrictor and fitted it to my machine. It is quite unnerving to unscrew the nut. I did fit the restrictor (against the advice on the store page) to the side with the heating element since there is way more space. I don't see how you would fit a 24 mm wrench without removing all other tubing as well. Just stuff some rags under the pipe to protect the heating elements contacts and possibly let it dry before plugging in again. Also I heated the nut with a torch to burn the glue which seems to be used and to widen the nut. Then bending the tube to the side just enough to put the restrictor in, which fits very snug by the way, while water spills out. Fun!
Now the machine runs noticeably cooler. I can drink store-bought Italian espresso and it tastes like it should. As someone who started on a Europiccola I think I prefer the lower temperatures on my machine. Normally I would drink espresso from the mid-range while sometimes dabbling in very light or dark roasts.
I hope this helps someone to decide if the mod makes sense for you. The installation is definitely doable but you should not rush it.
hi nico. i completely agree that it is a lot easier to fit to the right hand (heating element) side of the boiler. i completely agree that the restrictor is the way to go for owners who are only interested in traditional espresso roasts.
Wouldn’t another option be to adjust the pressurestat a little lower to bring the boiler temperature down a bit?
I can’t help but think that the issue with dark roasts are only with the darkest roasts. I struggled for awhile to get good results with dark roasts on my Cremina but eventually I nailed it. And the Cremina can run much hotter than the LR and doesn’t have the same consistency.
the key difference with our machines is you can move the brew temperature without pushing the machine out of equilibrium. with our machines you dont need thermometers stuck all over the machine like a high school science experiment; you walk up and pull a shot and you get the same result as the last one you pulled
shifting boiler pressure doesnt move the brew temperature that much, that is the basic problem; by the time you have dropped the boiler pressure enough you've got anaemic steam power, and its the same at the top end. that is why on all of our current range of londinium machines you leave the boiler pressure alone to run 0.8-1.0 bar and adjust brew temperature using the thermosiphon where small changes induce large changes in the taste in the cup; that is what the last 8 years of my life has been spent doing; investigating this age old issue and finding a solution to it. its now done, it works.
sticking a restrictor in the thermosiphon pipe is about as easy a task as you will get; you certainly should not consider buying our machines if you feel concerned about opening the thermosiphon pipe where it screws onto the heat exchanger and pushing in a restrictor and screwing the pipe on tight again; it is the largest and therefore most robust pipe on the whole machine
Thanks for clarifying Reiss. I agree with everything you’ve said. In fact, it’s the main reason I prefer the Londinium to the other spring levers out there. Some have PIDs, yes. But when you lower the temperature enough to have an effect, people report that steam pressure becomes anemic - this seems like a design flaw. I’d prefer the simplicity of the londinium.