Do you change your routine when using a bottomless portafilter?

Beginner and pro baristas share tips and tricks for making espresso.

#1: Post by MattJ »

I noticed several of you are big advocates of the naked portafilter especially on the La Pavoni Europiccola.

I am curious if you change the way you prepare or pull the shot with the bottomless???

It seems there would be less pressure in the stroke as the surface area that the coffee is exiting the group is much greater than the hole and spout.

I do occasionally get cracks in my pucks and am not sure exactly why, so I am considering converting. I'm pretty pleased with my morning coffee so I don't want to mess with too many factors :wink:

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#2: Post by HB »

I advocate a bottomless portafilter as a diagnostic aid; I like them because they're easier to keep clean too. My preparation routine is unchanged, though I subtract a few seconds from reported beading time if someone asks (i.e., if comparing the appearance time of first drops on a spouted portafilter, I add 4 seconds versus a bottomless portafilter).

In terms of the espresso itself, some report the texture is lighter / more airy with bottomless portafilters. If the additional fluff factor bothers you, try allowing the pour to run the full depth of the cup by streaming the flow along the side instead of dead center (or alternatively, give the espresso a swirl before drinking).

You mentioned "cracks in your pucks". I'm not into puckology; if the pucks have the same look and feel, they're good enough in my book. If the extraction is channeling, the bottomless portafilter makes in painfully obvious. I pay specific attention to how the espresso beads on the bottom the first few seconds. Ideally the entire bottom should bead at the same time, indicating the water is flowing evenly through the puck. Bad signs are "donut extractions" (center has no flow, usually due to side channeling) or center-heavy extractions (most flow from center, usually to due to too high a dose restricting flow along the perimeter, especially if the dispersion screen is domed/has a center screw).
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MattJ (original poster)

#3: Post by MattJ (original poster) »

thanks for the response, Dan.

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Randy G.

#4: Post by Randy G. »

The only change is to be more careful in preparation to avoid channeling and sprites. In terms of sprites, these are virtually undetectable with a standard portafilter but easily seen with a bottomless.
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#5: Post by cannonfodder »

Cracks could also be a sign of to high a dose. lock your portafilter in, then remove it. If there are cracks in the unused puck or the surface of the puck is scuffed or disturbed by the shower screen you may want to cut a gram or more off your dose.
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#6: Post by RayJohns »

I only ever use a naked portafilter. It's nearly impossible to properly diagnose shots without one.


MattJ (original poster)

#7: Post by MattJ (original poster) »

cannonfodder wrote:Cracks could also be a sign of to high a dose. lock your portafilter in, then remove it. If there are cracks in the unused puck or the surface of the puck is scuffed or disturbed by the shower screen you may want to cut a gram or more off your dose.
Thanks, that's a good tip.

I'm using a lever, so to use or not to use the Fellini double pump is another factor in the whole puzzle.

It was pointed out to me that it should be quite obvious that the pressure is the same with a bottomless. I have a hard time digesting this obvious logic. Can someone help me?

It seems that both are open systems, yet one has more surface area of outflow than the other. I would think that the bottom of the portafilter creates some pressure against the filter. In a system that uses "15 bars" of pressure I don't know what that would translate to as far as changing the tamp, dose, or in my case force on the lever.

In layman's term say you had a gallon of jello and you were going to push it through a cylinder - would you need more force to push it through a cylinder with an opening as big as a grapefruit, apple, cherry, or a needle sized opening? Hmmm... doesn't seem so obvious to me. Perhaps at the consistency of espresso these two outflow sizes don't effect the pressure? I dunno. That's why I asked.

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#8: Post by Kristi »

Matt, the pressure is built up against the puck, which has a hydraulic opening of the bottom of the basket where the holes are. Changing the container makes no difference - regular holder with spout, no spout, or bottomless. If you use a basket with a wider (holed) bottom, then things change.

MattJ (original poster)

#9: Post by MattJ (original poster) »

So is there dead space under the bottom of the filter basket between the basket and the portafilter?

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#10: Post by Kristi » replying to MattJ »

Most definitely! - a few millimeters on the sides and a few millimeters on the bottom - of course, more toward the center of the bottom...

You'll find some nice info and a pic at the top half of Randy Glass' site:

Just look at the top part (the NON-pressurized pf).