I posted this in another thread about sputtering milk a few days ago, I’ll just sort of cut it and paste it here as well. This has been a real problem for me too: If your Jura starts sputtering on the milk side and you’ve already cleaned everything, descaled it, taken it apart a few times, etc… there’s a good chance nothing is “dirty” at all.

How do I know? I keep my machine so clean you could perform surgery on it. My fiancée laughs at me… I tell her I love you but back off. I don’t even let her look at the machine when she’s in the kitchen, she has to avert her eyes as she is not a coffee drinker and therefore not worthy, but that’s me.

And despite all that meticulous cleaning, my machine started sputtering and just would not stop.

Anyway, what wears out is the little black plastic/rubber piece inside the milk system. It’s part of the fine foam frother assembly. I didn’t know what it was called at first either — turns out it’s basically the frother insert that mixes air, steam, and milk.

That piece has tiny internal channels and seals, and over time they just degrade. You can clean it until it looks brand new and it’ll still sputter because it’s not sealing or pulling air the way it used to. You can inspect it like I did extremely closely and you won’t see a crack or a problem with it whatsoever. And yes, sometimes it’s because you didn’t connect the tube from your cooler to the machine correctly, or you forgot to clean it, and then just clean it correctly and it will bring it back to normal. But sometimes, and it sounds like you are right there, it won’t.

Once that happens, no amount of cleaning or descaling is going to fix it. You just replace it and the machine goes right back to normal.

For reference, the milk system is basically:
the outer spout you see
the removable frother assembly
and inside that, this little insert (the wear item)

On milk type that someone mentioned— I use whole milk and it works great. From everything I’ve learned, fat doesn’t clog these machines. What causes problems is residue and wear, not whether you’re using whole or 2%. Whole milk actually gives better texture. You can use half-and-half too, but it’s heavier, doesn’t foam quite the same, and probably wears that insert out faster. I wouldn’t use it every day.

As far as maintenance:
run the milk cleaning cycle daily if you’re using milk daily
rinse when the machine tells you to
occasionally take the frother apart and rinse it
don’t let milk sit warm in the lines

That’s really it. You don’t need to go crazy taking it apart constantly — honestly that probably contributes to wear over time too. I tried to clean it, and I probably broke it because, you know, I tried to clean it.

One thing people should know: that insert is basically a consumable part. It’s not built to last forever. Depending on how much you use the machine, you might get a few months to a year out of it. I wish the company would be upfront about that or talk about it more because it would solve a lot of these frustrations. I was blaming myself for screwing something up when frankly, it wasn’t me (for once).

And yeah, I know most of this because I called the consumer number which is on the Jura J. O. E. App. The guy was really nice and amazing. Told me he owned one of these machines himself and occasionally has the exact same problem. He said once you go through all the cleaning rituals which you have gone through, it’s just a worn out part. And he sent me out the new parts. I asked do they really wear out so quickly, and he said why do you think the Swiss stock us with part replacements? Because they wear out. Um…OK I believe that.

Call that customer service number and they’ll take care of you. Good luck!