Hello there guys at the home barista forum.

It has been some time since I took a funny decision in my life which is that I try to pursue a career in coffee while doing my masters in Computer Engineering. A lot of things happened since then, also. I got a job, then got fired then got another job which is though much more tough (more working hours and much less salary) still gives me the opportunity to develop my passion for coffee and to pursue a personal life of some kind outside of Saudi Arabia.

Long made short, I am working again after a long struggle for many months and I thank the lawyer member of this forum for suggesting that I go to that coffee and tea convention last year in Dubai, it was where all my coffee journey begun.

I am now working in a restaurant that uses a 3-group La Marzocco Linea espresso machine. The restaurant is 24 hours which means that the espresso machine is never turned off which concerns me a bit since Arabs are very bad in maintaining equipment and I have a feeling that many parts inside needs to be replaced/rebuilt. Anyway, one thing I noticed is that the steam boiler pressure is always from 1 to 1.2 bar but never beyond that. This coupled with what people mention about those machines (that they feature an independent steaming/brewing performance and that the steam boiler pressure is usually set to 1.5 bars) along with my observation that the steam power (pressure not sustainability) is not that impressive especially in large pitchers makes me willing to see if there is something I can do to achieve superior micro foam with this machine.

That day I steamed in an extremely small pitcher that I own and the micro foam was superior, it allowed me to pour a rosetta in a half-espresso half-milk macchiato cup, which made me think in the direction that maybe there is something wrong with the steam boiler pressure.

Yet there are other funny things which I want to mention: The steam boiler pressure is very sensitive to steaming, that is, it is not as "stiff" as you would expect it to be in such a huge-boiler machine (ehem, huge to someone who was originally a home barista). Furthermore, after steaming the boiler pressure gauge rises fast to 1.2 bar, but after that it drops over the course of 30-60 seconds to 1 bar again. Funny right? Once you finish steaming it raises to 1.2 and then after the steaming is finished it starts dropping again, which puzzles me :S

Is it possible that there is a steam leak and in that case wouldn't I be able to see it or hear it? Dunno.

I read the troubleshooting pages in the La Marzocco Linea technical manual I found online and checked the field "Not enough steaming pressure". I am not sure if it is possible that I have "partially damaged heating element" in the steam boiler but maybe there is something wrong in the pressurestat, also.

Another possibility is that the pressurestat is simply set to low pressure. Is this also possible and then why do the boiler pressure drop significantly when I steam and then raise again and then starts dropping slowly by 0.2 bars? It is all confusing to me but I have very little experience on this machine so maybe this is not confusing to someone who knows a lot about it, which is why I am posting here.

Please offer suggestions and ask me questions. I can take photos and inspect the machine for you, as long as you will help me achieve the superior steaming performance I am eagerly looking forward to have.

Thanks :^)

I do not understand your problems. All about your machine seems to be OK. If you want higher steam pressure, just set properly the pressurestat. The steam pressure may be set to 1.4bar, but also 1.1bar is not a bad idea. It depends on you and what do you want to obtain during your work. At the begining of my experiences with Linea, I used to use 1.3-1.4bars. Last years, I set the pressure to 1.1bar — it is perfect for small pitchers.

Again I agree the steam pressure seems to be running correctly. I have mine set exactly the same (1-1.2 bar). If you set it higher you risk a higher likelihood of failure.

Okay since I posted this I have improved and now I pour nice rosettas but the milk is still not nearly as smooth and velvety as with my La Pavoni. The fact I can achieve superior microfoam with a domestic machine makes me think that there is something that I can do to improve this machine's steaming performance.

Maybe there is nothing wrong with the machine but then please tell me where is the pressurestat is located and what do you have to say on steaming with higher boiler pressure. Most of the time I use very large pitchers in this cafe I am now working in because they serve huge milk drinks which is something I do not like but results in me using large pitchers most of the time. I think a higher boiler pressure can help me obtain better milk.

Please give me advice or elaborate more. It is also appreciated if you can send me YouTube videos of some of the good steaming positions on the Linea, cause the design of the steam wand is kind of different from other machines. I once saw a video of Heather Perry steaming milk on this machine, resulting in milk movement similar to how Scott Calaghan (the Australian barista) steams milk. The movement of the milk in both cases is very violent (even in a large pitchers) making me think that those guys use higher boiler pressure. What do you guys think?

Could this be a problem with the level control for the steam boiler? If it is over-filled the quantity of steam may be low, also the very quick recovery might tend to that conclusion.
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KDM

Our linea has two sorts of tip. One allows much more steam through than the other.

On the unrestricted(as we call it) tip doing a little jug with 5 oz or so milk is hard.
On the restricted it is hard to do a 3 latte jug.

You may have two of the 'restricted' tips, they are not enough to properly do massive jugs.

The boiler runs 1.1-1.3 unless you get regularly hit with americanos and take the water out of the boiler- this is our biggest threat to steam production and normally run a tea urn if busy.

The difference between the two tips we have is much more significant than .2 increase in boiler pressure or changing the fill level.

Also have you checked the tip is not full of cheese? who knows what went on before you got there

duke-one wrote:Could this be a problem with the level control for the steam boiler? If it is over-filled the quantity of steam may be low, also the very quick recovery might tend to that conclusion.
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KDM

I'm glad you mentioned this. The sight glass should be around 2/3 full. The adjustment is very easy and if the glass is full of water, you won't get decent steam and probably the sensing probe is coated in scale.