The p-stat on the LI gets it to a general pressure and resulting group temp respective of its environmental ambient temp condition. Even if you desired finite control of the p-stat, to .5C, it would be difficult at best and very time consuming at worst probably requiring a completely different p-stat (for PID). And in the end you'd be right back to a machine you opted not to buy in lieu of the LI
And if one prefers a different bean each week then dialing in the LI isn't much different from any of the other espresso machines I've used/owned. I suspect I am not much different and prefer not to order several pounds of a new bean, to allow for proper dial in, when I can be quite satisfied with the 1/2 dozen or so beans from roasters I can and have proved to be able to rely upon for consistency.
As others have so eloquently stated: The beauty of the LI is its utter simplicity and lack of electro-mechanical failure prone systems...
Grind, tamp, roast, it all has something to do with taste and I just work the flavors I prefer. Sadly my wife prefers a different flavor so I need to roast a different bean for her.
So this goes a little against the PID philosophy of tweaking the temperature (or, at least, playing around with numbers) for different types of bean. Are there certain very light and difficult beans that would work better in a PID machine? Perhaps, but I haven't found them. The inbuilt temperature/pressure profile of a lever groups works its magic, and it's a magic that seems to outweigh the benefits of fine temperature tuning.
Coming from someone who has used a PID machine as his primary espresso device for the last couple of years I'd like to add a bit to this.
1) Even with a PID you don't tend to play with it that much. Yes, I'd adjust it for various beans, but that usually means once or twice a month at most.
2) A lever is an entirely different beast than a pump machine.
A pump machine extracts at a constant pressure and constantish temperature.
A lever machine starts at a high temp and high pressure and drops throughout the shot. It doesn't need to be adjusted for each different bean because it already passes through an optimal temperate range for any bean.
I believe this is why it's so easy to just walk up and bang out exceptional shots on the L1.
A lever machine starts at a high temp and high pressure and drops throughout the shot. It doesn't need to be adjusted for each different bean because it already passes through an optimal temperate range for any bean.
I believe this is why it's so easy to just walk up and bang out exceptional shots on the L1.
While on subject of declining pressure profile: I asked this question in another thread and AFAIK never got an answer. The LI spring certainly appears to be a linear rate spring not a progressive rate spring. Given water doesn't compress I don't understand how the pressure drops apart of normal extraction ratios...given its fixed rate spring.
I could be wrong, but i believe that once the puck has swollen at the start and the oils have started extracting, the water resistance in the puck decreases Whereas a pump machine tries to keep the pressure constant
Dan Streight post=1657 wrote: The LI spring certainly appears to be a linear rate spring not a progressive rate spring. Given water doesn't compress I don't understand how the pressure drops apart of normal extraction ratios...given its fixed rate spring. Anyone?
I could be completely wrong on this, but I understood that the design of the cams in a lever group does mean that spring pressure is not linear.
Yes, a big cam action! I forgot about that thing. It must change the pressure curve since you can feel the different pressures as you pull the lever. Sort of like a compound bow in archery.
Kfir, was that a Bosco 2Group? Thanks for the video!
6 months ago I made the clip below. The initial spring pressure is visible. At the first pull, pressure is lower than the second as the second time there's less space for air in the PF and all the spring power is shown, topped up with me pushing the lever up a bit for a second, to demonstrate how one can force up to 11 bar if one wants, at the start of the extraction.
Note that this is a no-coffee puck measurement, so no one-on-one conclusion to be drawn about coffee extraction. It just shows initial spring pressure and a gradual decline of it as fluid is allowed to flow out.
In the first pull, one can see the pressure relax over the time of the shot. In the lower pressure, this gauge gives up and doesn't show the numbers. This gauge seems to be best in the actual brew range, designed to check if the brew pressure of an OPV is set correctly, not for exactness in the lower range.
That's it : I got my Londinium 2 days ago ! Very fast shipping (thank you Reiss) I have to learn how to managed with the machine but I guess, it won't take a long time. Thank you everybody for helping me to make the good choice. Jean-Phi
Comments
And if one prefers a different bean each week then dialing in the LI isn't much different from any of the other espresso machines I've used/owned. I suspect I am not much different and prefer not to order several pounds of a new bean, to allow for proper dial in, when I can be quite satisfied with the 1/2 dozen or so beans from roasters I can and have proved to be able to rely upon for consistency.
As others have so eloquently stated: The beauty of the LI is its utter simplicity and lack of electro-mechanical failure prone systems...
I think we've beat this dead horse...more dead :D
Coming from someone who has used a PID machine as his primary espresso device for the last couple of years I'd like to add a bit to this.
1) Even with a PID you don't tend to play with it that much. Yes, I'd adjust it for various beans, but that usually means once or twice a month at most.
2) A lever is an entirely different beast than a pump machine.
A pump machine extracts at a constant pressure and constantish temperature.
A lever machine starts at a high temp and high pressure and drops throughout the shot. It doesn't need to be adjusted for each different bean because it already passes through an optimal temperate range for any bean.
I believe this is why it's so easy to just walk up and bang out exceptional shots on the L1.
While on subject of declining pressure profile: I asked this question in another thread and AFAIK never got an answer. The LI spring certainly appears to be a linear rate spring not a progressive rate spring. Given water doesn't compress I don't understand how the pressure drops apart of normal extraction ratios...given its fixed rate spring.
Anyone?
Whereas a pump machine tries to keep the pressure constant
Watch this video, although this is not a L1 I believe it shows a very similar pressure profile:
Kfir.
Kfir, was that a Bosco 2Group? Thanks for the video!
Thanks guys!
No, the description says it's an old 60's Australian made machine.
It doesn't matter, I believe the L1 will show a very similar profile...
Kfir.
Note that this is a no-coffee puck measurement, so no one-on-one conclusion to be drawn about coffee extraction. It just shows initial spring pressure and a gradual decline of it as fluid is allowed to flow out.
In the first pull, one can see the pressure relax over the time of the shot. In the lower pressure, this gauge gives up and doesn't show the numbers. This gauge seems to be best in the actual brew range, designed to check if the brew pressure of an OPV is set correctly, not for exactness in the lower range.
That's it : I got my Londinium 2 days ago ! Very fast shipping (thank you Reiss)
I have to learn how to managed with the machine but I guess, it won't take a long time.
Thank you everybody for helping me to make the good choice.
Jean-Phi
Thank you for choosing LONDINIUM
Please feel free to post in the French section and I will translate it, if that helps
Kind regards
Reiss