I recently purchased an Alex Duetto (with Macap M4), and even after a couple of months, I'm still coming to terms with pulling consistent shots, dialing in grind, etc. I've been using a Rancilio bottomless portafilter from day one to help evaluate my shots, but it's been frustrating getting good shot-to-shot consistency without any channeling in the puck.

I've been using the double basket that came with the machine for the most part. I tried a few tamping routines, like light tamp + heavy tamp, light tamp + tamp around the edges + heavy tamp, etc. I eventually decided to just stick with a single heavy tamp and no knocking the basket to eliminate any sources of channeling.

Two annoyances with the (Izzo?) basket: It's wider than my 58mm RB tamper, so I miss the edges when tamping, and it holds SIGNIFICANTLY more than 14g of coffee. This is an important point to me because it makes it very difficult to effectively use grind distribution techniques unless I want to pull shots with 19 or 20 grams of coffee. I've been sticking to 15g from the beginning, and it's difficult, if not impossible to effectively distribute and level grinds when they're so far below the top of the basket (especially around the edges). I have also noticed that several of the perforations in the middle of the basket are not formed properly, which noticeable affects the way the shot pours.

I noticed the Rancilio triple basket that came with my bottomless PF fits my tamper perfectly. I wanted to replace the double basket with one that had proper perforations, and the selection from stores in Canada was not great, so I ended up just ordering a Rancilio double basket from Green Beanery. It arrived yesterday, and I've been trying it out this morning.

It's much, much smaller than the one that came with my Duetto. It's pretty obvious it was designed to hold around 14g of coffee at typical espresso grind, before tamping. Unfortunately, because of the way it's shaped, I cannot tamp with my RB tamper. It binds on the side of the basket before I can put enough pressure on the puck, and there is always a deep impression from the dispersion screen. The fit is so tight that the suction from removing it from the basket is enough to release the entire puck from the basket and pull it up. I discovered this by dumping a freshly-tamped basket of grinds down my shirt

Is there another brand basket I should try, am I making too much of a deal out of the perforations and volume issue with the Izzo basket, or what?

I'm concerned with tamping because I regularly see the effects of channeling in the puck, both when brewing, and when knocking it out afterwards.

My coffee is SM's Espresso Monkey blend, as fresh as I want. I don't usually bother even trying for several days after roasting, since I usually just get a cup of crema that quickly dissipates. A week or more is better in this respect.

I can only weigh my dosing to within 1g, but I can probably eye it a little closer by volume when repeating shots. I never bothered to try the weighing on a 0.1g scale routine because it would have cost so much just to get one of the ridgeless PFs. Espresso Parts wants $30 to ship one up here, which is ridiculous.

I believe the brew pressure shows around 9.75 when brewing, which is as the machine came from the vendor. I've never tried to modify this.

Ian, I'm not concerned about the puck, I just wanted to point out that I can see the effects of channeling when pulling shots, and examining the puck afterwards shows clear signs of this.

I am home roasting, both to the level recommended by Sweet Maria's (a little lighter than typical), and sometimes darker. This has very obvious effects on the resulting espresso, but doesn't really make much difference to the shot consistency. I haven't tried any high-end commercially roasted espresso.

I will see what I can do about getting a 0.1g scale and weighing grounds more precisely. My M4 is a (stepless) doser model, so I don't have clumping issues. I usually load coffee in the hopper as I use it, but I don't specifically weigh it out because of grind retention in the chute, doser mechanism, etc. I am quite careful about cleaning out spent grinds after each session.

I typically brew at 200F, and try not to vary too much since I'm still getting other factors under control. I have not verified the PID offset with a thermometer, but I do recall performing the suggested routine of checking the temperature at which the water flash boils. I am pretty slow at cleaning, grinding new coffee, weighing, etc. so the machine has a good amount of time to recover between shots.

To put this basket issue in perspective, I have been pulling shots using the original Duetto double basket and 18 grams of coffee over the last couple of days. I am able to get consistent shots this way, even with the perforation issue I mentioned earlier. Filling the basket makes it much, much easier to evenly distribute grinds following the various distribution and levelling methods I've seen demonstrated. Tamping is relatively simple and has much less of an effect on the resulting shot. I am not seeing any channeling in the shot or the puck. Is it typical to fill the basket like this rather than attempting to pull shots with smaller amounts of coffee in a larger basket?

Gus, I wouldn't have thought the perforation issue would be such a big deal either. There are three holes that aren't stamped out properly in a line near the centre of the basket, and I can often see a void in this area when pulling a shot. I would be happy to try some different baskets, but the selection here is very limited, so it would have to be a special (expensive) order from somewhere like espressoparts. Are there any other accessories I should consider purchasing at the same time? Do you have any specific basket suggestions other than the ridgeless LM?

Update:

I've changed a couple of things about how I dose, and it's made a big difference to the shot-to-shot consistency. First, I bought a 500 x 0.1g scale, and removed the spring clip from my bottomless PF for easy basket removal. I settled on 18g for doubles in my original Izzo basket. There is lots of head space in the basket, but I can see an impression of the dispersion screen on the puck when it's finished.

I also completely changed the way I distribute the grinds with the doser on my M4. In the past, I was just grinding enough coffee for a double, then dosing it out in a couple of sweeps. I realized this would be much more effective if I constantly dosed into the PF basket as I ground, which I've been doing ever since. I end up with a nice mound of fluffy grinds that I flatten/distribute with my finger and tamp.

Now that I've eliminated some of the variables, I can dial in the grind a lot more easily and get nice consistent pours. I still get more blonde gushers than I'd like, but things have improved to the point that I'm able to make milk drinks without worrying about watching every shot like a hawk.

I am still interested in picking up some other PF baskets. My main motivation now is to be able to line up a few pre-dosed shots and pull them back to back, instead of dosing, weighing, adjusting, weighing, etc. for every shot. I'll probably order from somewhere like espressoparts so I can pick up a few other assorted items at the same time. Can anyone suggest a good basket to continue my 18g dosing? I just don't want to end up with another useless basket like the Rancilio.

Thanks, that is a good option if I just skip the other bits and pieces I was thinking of getting. They're described as Le Marzocco ridgeless doubles, but I'm not sure they are the same as the ones espressoparts sells (though neither are actually LM products). I've read the espressoparts one holds 19-20 grams updosed, like the double basket I'm using right now, which is what I'm looking for. Do you have any experience with the ebay ones?

The seller is pretty helpful and offered to ship 4 or 5 in a small flat rate priority box.