podo98 wrote:I have read Dan's review on the La Cimbali and I was a little worried that the machine was not that forgiving when it came to average technique especially as compared to the La Spaziale S1 Vivaldi II or the Vetrano. People rave about all machines but I worry that with the La Cimbali i may biting off more than I can chew. I am considering the La Cimbali because there is a local dealer in houston who has both the machine and the Mazzer Mini E grinder.
The current Junior model "D" or M21, uses a rotary pump. Unlike the earlier vibe pump model, the pressure ramp up is immediate and the puck receives ~9 bar almost instantaneously. As a result, proper dosing, packing, and distribution are necessary or you are likely to get channeling, which will be most obvious with a bottomless portafilter.
Apparently, this is more likely to occur with North American dosing, which tends towards updosing of double baskets. My normal operating procedure on my Cimbalis is to use about 18g of ground coffee in a double PF that was nominally designed for 14. Jim Schulman has done quite a bit of research recently on the whole topic of espresso shot dosing and extraction ratios. As a part of that experimentation, he has discovered that channeling is much less likely to occur when typical Italian dosing standards are followed, e.g. 12-14g in the double basket in lieu of N. American doses. Presumably this would reduce the likelihood of channeling on a Cimbali Junior. Jim has also observed that in many cases with many coffees, a better tasting shot results from these lower doses; of course, one would need to grind finer if the dose used is less than what has been used previously. I have myself only just begun to experiment with this and have little first hand experience, especially in how it effects channeling.
In my own rotary machine, I performed a modification which was recommended to me by Michael Teahan, who occasionally posts here. This modification involves using a pressure regulator on the input water side, combined with a solid state "delay on make" timer on the rotary pump circuit. These timers are cheap and cost about $25, and are cube shaped; they will fit in unused space in the under drip tray electronics compartment. With fairly simple wiring, the timer will interrupt the flow of electricity to the rotary pump for a user-settable period of time. In my case, the pump is delayed for 6 to 7 seconds, however the input solenoid valve opens as normally. Since I have my pressure regulator set at about 3.5 bar, and since the solenoid still opens as normally, when the shot button is pushed water enters the portafilter at around 3.5 bar for the initial 6-7 seconds and this serves as a "poor man's preinfusion." After this period of preinfusion, the puck is then hit with the full 9 bar. The net result is much less frequent channeling.
Any modification like this is probably going to invalidate your warranty, so it would need to be done later, after the warranty has expired. Another modification I have done to this and also to my older pourover Junior, is to control the boiler temperature via PID (electronic temperature control) in lieu of the pressurestat. I have been able to obtain repeatable shot temperatures with this approach combined with low volume flushing.
The major advantage of buying a Cimbali Junior over most other machines is that they are generally "bulletproof," giving long service without much need for repair, if treated well. They are also very well laid out internally and easy to work on for most owners with a little bit of mechanical skill.
I like my machines a lot, and they produce consistently tasty shots.
All of the above having been said, the stock Cimbali D is now, in my opinion, becoming a dated design and could use a little refreshing. Hopefully this will happen soon, although I have heard nothing about changes being made imminently.
ken