Are La Marzocco boilers forever?

Need help with equipment usage or want to share your latest discovery?

#1: Post by georgemvg »

Hi all!
I have a Linea from 2012, working its in a cafe.
As time passes, flavor of coffee is not good.
Almost whatever coffee I want to extract, has a flat flavor like they are the same (mostly blends).
The machine has a water filter for hardness as well as clorium and metals, but not RO treatment.
I have asked several technicians, some say that after the annual service the machine become almost as clean as original state.
Some others, that old machines have to be replaced.
I want to make a water analysis. Should I analyze the water that comes from the brew boiler?
Can bad flavors get stuck to an old boiler, or this is not the case with the marzocco's stainless boilers?

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#2: Post by Jaroslav »

What grinder(s) are you using?

georgemvg (original poster)

#3: Post by georgemvg (original poster) replying to Jaroslav »

Mazzer Major and Super Jolly

Team HB

#4: Post by samuellaw178 »

Flat tasting coffee could be caused by several reasons but the boiler would usually be the last thing that comes to my mind. So I think the boiler is quite unlikely to be your problem, but not impossible.

Have you tasted the water that comes directly from the group head? Flush some water through the group to give it a quick clean, and then flush another 50-100ml into a cup, and let that cool down. Taste the water and see how it tastes.

If it tastes rancid/coffee flavour, maybe you just need to clean/detergent backflush the group head (has it been done recently? If not unscrew the shower screen to check if there's any coffee oil built up).

The other reason is probably what Jaroslav was alluding to. If the grinder is not cleaned and has been used with a hopper, then the retained coffee can also cause your coffee to taste flat no matter what you do on the machine end.

georgemvg (original poster)

#5: Post by georgemvg (original poster) replying to samuellaw178 »

The machine is cleaned every day with cafiza/backflushing. End user cleaning, is done thoroughly, so i think this is not the case.

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#6: Post by Jaroslav »

And when was the last time the burrs were changed (or at least cleaned)?

These are Mazzer's recommendations:

Mazzer Super Jolly (64mm flat burr) - change at 400kg coffee throughput
Mazzer Major (83mm flat burr) - change at 590kg coffee throughput

I don't know how busy your shop is or how old your burrs are, but it's definitely something you should look into.


#7: Post by Pressino »

Probably the surest way to see if your machine is the problem would be to make espresso on another machine, preferably another linea or at least a good dual boiler machine, using the same water supply beans, machine and grinder settings (boiler temp and pressure mainly), and puck prep to see if there really is a significant difference in coffee taste. If there is then that does point to a problem in the machine. If not, it could be a problem with the water or any of the other items I mentioned except the machine itself.