Putting the knife to Gaggia · Wednesday August 2, 2006 by dave
... well, sandpaper anyway.
After long and faithful use, I was finally sufficiently fed-up with the shower plate in my Gaggia Espresso to do the unthinkable. I hauled it out and within moments had filed down the exaggerated ridge that surrounds the shower screen, using some fine sandpaper and a filter mask (didn’t feel like breathing in aluminum dust, though the procedure was pretty clean — it doesn’t hurt to be cautious). While more than a mm of ridge remains – well more than enough to hold the screen in place – this ridge is no longer lower than the center screw and my Espresso is no longer cross-purposed as a trenching machine.
For those that may not be familiar with the otherwise wonderful Gaggia domestic espresso machines, one of their sometimes frustrating features is a pronounced ridge surrounding the shower screen that is in fact much lower than the center screw. This feature has the disadvantage of digging a ditch in the side of your puck if you do not compensate for this in your dosing.
For everyday dosing where you want some distance between the shower screen and the puck surface, this isn’t so much of a problem. It enforces a stricter gap than you might otherwise use, since the ridge hangs lower than the screen. Dosing in the high end of normal, dosing normally (or even low) with coffee exhibiting high expansion, or updosing is trickier. I am becoming convinced that the depth of this ridge may contribute to channelling mid-brew, even though the contact occurs during coffee expansion and not when locking in the dry puck. I’ve seen too many circular cracks along this impression on pucks that otherwise were OCD-distributed and nowhere near the screen to begin with.
To be fair, the Gaggia basket consumes a lot of coffee and not all coffees will react favourably to higher dosing. However, they won’t all react favourably to lower dosing, either. This tiny project was not initiated to change dosing, so much as to try and prevent increased channeling that may in some cases have something to do with this ridge.
Initial results seem favourable, but insufficient to draw any conclusions. A screen and ridge impression is a common feature in spent espresso pucks. When occurring after the coffee has expanded during the brew cycle, this is completely normal and often desired. Channelling can also occur for many reasons, and is likely most often caused by user error. We often warn users that espresso problems are often “on the other end of the portafilter,” so to speak. However, the overly deep ridge on this enthusiast’s Gaggia Espresso has worn out its welcome, and I’m giving this slight modification a go to see if it benefits my results.
Dave
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Dave, the Gaggia Espresso is the machine we use here at the office. Please let us know if you find this modification helpful, so we can do the same. Thanks!
— Bradley Pascoe Aug 3, 08:35 am #
Hello Bradley,
Good to hear from you!
I’m going to give it some time before drawing conclusions, but my expectation is that it will help to make an already good machine a bit more forgiving and versatile. At the least, no more ditches in pucks that are otherwise below the screen, which theoretically would help in an office environment where time constraints fight with quality and consistency.
— dave Aug 3, 12:58 pm #
I don’t know when the above was written, but I think I’m having the same problem with a second-hand Gran Gaggia. I wondered if the shape of the shower-holding plate was designed for handling coffee pods. I can’t put the right amount of grounds in the one, or the two shot filter without creating the ditch effect, even when locking in the portafilter. I only get about 4mm of clearance in which to fit the puck. Anyway, I was interested to see your solution. I might have to resort to the same step. I’m trying to find out if there is a replacement part with less of a ridge. Not much luck.
— James Stuart Jun 2, 05:26 pm #
I wonder about normal wear and tear on the portafiter… I mean, the Gran Gaggia is getting up in years. I imagine that you are using the double basket on this unit.
— Colin Newell Jun 3, 10:53 am #
James: Filing down the ridge has been working very well for me. No known problems after the better part of a year and no more ditching. As suggested above, this does not magically correct for user error in dosing and distribution, but it removes a sticky problem and does significantly improve dosing flexibility.
As for there being an alternate part, I doubt so unless the ridge was even worse on the Gran. This is a common part for most Gaggia home models, including the new Gaggia Achille Lever. My experience with the Achille was that the ridge didn’t pose the same problem, however, perhaps due to the different pressure profile.
— Dave Jun 3, 12:30 pm #