Anyone have any tips on best shot pulling technique on a La Cimbali Jr?? I've been mostly using the flush and go routine but today I tried flushing and rebounding and was totally amazed at how much of a difference it seemed to make with the current indonesian blend (PNG and Sumatra) I've been using. I'm suspecting that these coffee tend to like being pulled hotter than other blends, or It might be possible to attribute this to more of a spiked temperature profile during the shot - sold my scace, so I'm just guessing

Although I'm not currently using my (remaining) Junior much these days, I did have a ~15 year experience with two different ones, an older vibe pourover machine and a more recent vintage rotary machine (now in Heat Exchanger heaven). I even modified both of those machines with PIDs.

The Junior is not as easy to regulate shot temperatures on as many other designs. It was not initially designed for low volume use in the home, rather has a temperature stability design that relies on it being used to pull repeated shots in succession. Much has been written on this topic on this board, including Dan's review on the Junior which is available here: http://www.home-barista.com/junior-buyers-guide.html.

My advice would be that if you are using the machine principally for straight shots, to set the pressurestat at a rather low level. Assuming a deadband of around 0.15 bar, I would try to set it with a low end of around 0.7 or 0.75 bar, going up to 0.85 or 0.9 bar. See how that works for you. This will greatly diminish the amount of flushing necessary to use this machine in a low volume home setting. This should also provide enough steam to make "properly sized" cappuccinos, but if you are looking to make gargantuan milk drinks while also preserving the ability to easily control the temp on straight shots, I think you will find the exercise rather frustrating.

ken

One hates to disagree with Br'er Fox... But I don't know if he's had experience with the Casa -- which is slightly different than earlier Juniors. if you knock the boiler pressure down as much as he suggests you'll get impossibly slow steaming from Chris's "improved" tip.

Try using your regular water dance technique, filling the pf, a long cooling flush with the pf out of the group, then getting it in and pulling the shot as fast as you can. Even though the Junior recovers extremely quickly, it's not instant.... just almost. You probably have 15 seconds or so where the water temp is down a couple of degrees... at least at the front end of the shot.

BDL

I'm not sure what the fuss is but I've found my new junior to be very easy to dial the temp in. I leave mine on all the time and have found that if I bring down the boiler temp a little first thing in the morning or after being dormant for over an hour or so with a 10 second hot water tap flush followed by a big flush (mine is 120 ml) to flush the HX my temps are right at 198F, a double flush or small flush (100 ml and 60 ml, resp) results in temps hovering around 200F. After the above routine if I'm pulling other shots the temp stays around 198-200 consistently- I don't even worry about temps at all after that.

I have no experience with the Casa, but unless I am mistaken, there is no difference in its basic components vs. the regular DT1 rotary Junior. The changes in the steam tip I am unaware of, that is sure, however I'm surprised to hear that they are so extreme that turning down the pstat to the range I suggested would be a problem for occasional modest sized milk drinks.

If on the other hand one is trying to steam 20oz of milk or one prefers drinks like that, well then that is another story, as I stated in my original post. One could always replace the steam tip if need be, a very modest change requiring zero technical competence

Almost any commercial heat exchanger machine, most certainly the Junior in its typical iterations, will be easier to control for shot temperatures if the boiler pstat is set at the low end of the range (as is typically done in Italy, where giant milk drinks are not the norm and where milk drinks generally do not exist after about 9am).

ken

hmmmm .. i think i need to rush home and lower my pressurestat! I have a much older Junior with vibe pump but i think im running it at 1.1 or 1.2 .. hopefully it will cut down on my cooling flushes, and trips to the sink.

Ken,

Most mornings I make exactly one double latte for my wife, using 8 oz of milk. With Chris's slower tip -- now "stock" on the Casa -- and the p-stat at about 0.95, it takes about 15 seconds to get to 18 oz of chrome. However, with the p-stat at 8, it takes more than 25 seconds to produce adequate volume, and the texture and aroma aren't as good as with a faster steam.

Of course, my meager skills may have something to do with this; and/or there may be something unique about my machine. Or not. My best guess is that the new tip imposes a sort of threshold. Maybe the solution for javacat is to lower the pressure AND replace the tip with the actual La Cimbali spec tip.

When you get a chance to try out a Casa with the slower tip, it will be fun to see the degree of coincidence.

BDL

tomesd,

The issue isn't temperature stability with the DT/1, or even dialing in one preferred brew temp with it. The Junior makes a lot of things easy, those are two of them.

Rather, is varying the brew temp for one or two shots with some degree of control. As for instance, if you roast or drink a lot of different blends, and want to pull a shot of something which brews best at 2 deg F lower than your normal. The Junior isn't a PID controlled, double boiler machine like a La Spaz or La Marzocco, and that isn't something it's really designed to do. You can do it if you don't mind leaving the side panel off and screwing around with pressure (Ken's suggestion); and/or, with some fancy water-dancing (my suggestion). My way is easier but not as accurate nor reproducible.

BDL

I'm aware that it's not a discussion of temperature stability (the junior is well known for this with multiple shots), my point is that with the aid of a Scase an easily reproducible flushing routine is achievable that can provide variable temperatures- one only has to learn how their machines heat sink and boiler behaves in response to controlled, repeatable interventions. It's not to the tenths of a degree (who cares) but I've found that I can easily dial reproducible temp ranges, 202-204, 200-202, 198-200, etc, with the aid of the Scase to where I don't worry about checking the temps- I just know what range I'm in. The junior is one of the most stable HX's out there, and it's heat sink is very tunable IMO.

boar_d_laze wrote:tomesd,

The issue isn't temperature stability with the DT/1, or even dialing in one preferred brew temp with it. The Junior makes a lot of things easy, those are two of them.

Rather, is varying the brew temp for one or two shots with some degree of control. As for instance, if you roast or drink a lot of different blends, and want to pull a shot of something which brews best at 2 deg F lower than your normal. The Junior isn't a PID controlled, double boiler machine like a La Spaz or La Marzocco, and that isn't something it's really designed to do. You can do it if you don't mind leaving the side panel off and screwing around with pressure (Ken's suggestion); and/or, with some fancy water-dancing (my suggestion). My way is easier but not as accurate nor reproducible.

BDL

Actually, I would never (and have never to my knowledge) suggested that -- leaving the side panel off or for that matter removing it in order to adjust the Pstat on a shot to shot basis. The machine is not designed for that. The new machines have their Pstat (a Cimbali branded microswitched pstat) in the back, which would necessitate removing BOTH side panels and the back panel, held by a minimum of 6 screws. This is beyond impractical.

The only way to do this in a practical fashion would be to replace or control the pstat through a PID, which is what I did with my machines, however not something I would recommend that others do.

For the record, I do not agree that the Cimbali Jr. design is all that temperature stable unless it is used to pull repeated shots. All it takes is a bit of time and a Scace device to prove that fact. On the plus side the Cimbali group head is a massive block of brass that is bolted directly onto the boiler, and has the HX running through it and down into the boiler. On the minus side is the fact that the group head itself is largely responsible for the actual shot temperature delivered, and it can either massively overheat if left to idle for long periods (especially if the pstat is set high to allow for rapid milk frothing), OR it can lose a lot of heat if the room in which it is located is cold.

I live in the Rockies at around 6000 feet of altitude and most houses (including mine) do not have air conditioning. During the hottest part of the summer, people tend to open up their windows when the sun goes down and to leave them open until morning, when the house is again all closed up with the hope of staying cool until the following evening when the windows will again be opened up. This results in a pretty wide temperature swing in my kitchen from (potentially) a high in the low 80's F, to a low of around 60F. My shots were coming out several degrees cooler than intended in the mornings during the summer before I figured out what was going on (heat loss from head of machine due to cold surroundings, resulting in too-cold espresso shots). A well designed double boiler machine would not have this problem. I compensated for this problem by bumping up the boiler temperature with my PID, but doing this on the stock pstat controlled machine would be a non-starter.

Granted, most people probably do not have such widely fluctuating temperatures where their espresso machines are located, and during the fall, winter, and spring, this was not a problem for me. IT does however support the notion that the Cimbali HX design is only temperature stable in certain specific situations (high volume use in a location with a stable ambient temperature). "Excessive" milk frothing will also, over time, reduce shot temps. Getting temperature stability out of this machine in low volume home use becomes easier if the pstat is set at a lower level.

I would not be satisfied with milk frothing as described for the new Casa model with the boiler temp set down in the low range as I suggested (pstat setting of 0.7 or so, as the bottom end of the deadband).

My suggestion to those who have this machine and who enjoy primarily straight shots, would be to try the lower pstat setting that I suggested for a few days to get an idea of what it would do to your shot temps and flush routines. If you find that it works better for you, then I would locate a suitable replacement steam tip that will enable you to use the machine for both straight shots and occasional milk drinks. If it doesn't work for you, then bump up the boiler temp to a level that works better for your usage pattern.

None of the above is to be interpreted to mean that I dislike this machine or I don't recommend it -- I like the Cimbali machines a lot and in fact I may buy another one for a dwelling I am considering purchasing in a city where I expect to spend more time due to business interests. The changes in design that Chris put into his Casa model are with the interests of the average user in mind. Most N. Americans make LOTS of milk drinks, and a more restricted steam tip will allow easier plus higher volume of steaming with the pstat set at the higher levels typical for N. American usage. If instead you are mostly interested in making straight shots, and having easier temperature management, this steam tip modification might conflict with getting better shot temperature stability by reducing the boiler temp. That is all.

ken