Help Please: Gaggia Carezza - Descaling Woes - What to use? How to do it?


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Feb 22, 2020
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I have an older (10+ years?) Gaggia Carezza - not the new one with a bunch of automatic features, but one with a pro-size portafilter. It's not the prettiest machine, but it's served me well.

Overall, I've been quite happy with it. I had the pump lock up once, but got it fixed, no biggie.

In the past few months, I've started to have a persistent problem with a need to descale. The water shoots out of the screen at odd angles, and sometimes only one or two "jets" of water make it through. Eventually, it gets to the point where only a tiny bit of water comes through, a dribble of sour coffee which is obviously no good at all.

I've done the descaling with lemon juice mixed 2-to-1 with water (using the lemon juice you get in the little plastic lemons) a couple of times, and that seems to work ... for a week or three. But I can see even within a couple of days thinks are getting a little more clogged. I tried running three lemons-worth of juice through in a row, but after the first one it didn't appear to make a noticeable difference (and honestly it was clear that all the output ports behind the shower screen were not working perfectly, but enough of them were that the coffee was fine).

Can anybody recommend a more powerful approach to descaling? Will vinegar be more effective? The commercial descaling solution you can buy? Is there a better way to descale than just running the dilute lemon juice through the machine?
A few things to point out... for descaling ANY machine regardless of boiler material, diluted citric acid is fine. Very safe, very effective and leaves behind no taste/smell. Your problem with that machine could be some clogging in the group valve. That's a mushroom shaped rubber spring loaded plug that maintains boiler pressure when the machine is ON/idle. Anytime the least bit of material makes it to that area it can cause the problems you mention. I'd check that area as well as for any buildup around the shower screen, dispersion disc. IF clogging still seems to persist I'd tear the boiler down for a manual descale as if you keep using descalers chunks might break loose and keep causing issues.
Calcium and Lime Remover from ZEP PROFESSIONAL is the one I use to clean all coffee machine parts. It's very effective and safe to use. You can buy diluted version at many places or industrial strength at some supply store.

That might work fine for parts as in external, but I personally wouldn't run it through my machine. My go-to will always be Dezcal from Urnex, but I test the water I use often, which is quite soft and I hardly ever bother with descaling these days as proactive is far better than reactive.
Once you’ve got your machine descaled, I wonder whether you’d be interested in using something like Third Wave’s espresso-profile mineral supplement in R.O. or distilled water. I’d be curious to know whether it makes a long-term scaling/performance improvement over your current water (not to mention better tasting coffee!).