Hi,

I recently bought a used Mazzer SJ from a reputable seller. Prior to that I had been using a Rocky and been getting good pours with my naked PF with no sprites or channeling. Just solid pours coming straight our of the middle of the PF in a nice stream.

Now with the Mazzer I am having some issues - I am finding it very hard using the same dosing technique not to get sprites and channeling. I am grinding 14g by dose into the doser, dosing into the PF, redistributing using a chopstick, tap straight down on counter once, tamp and pour. Basically exactly what I was doing with the Rocky. Resulting espresso has more crema than with the Rocky but I am really struggling to eliminate the sprites and occasional channeling - which I never had with the Rocky. Machine is a Silvia but my routine on the machine side has not changed.

Any help?

Thanks,
David

If you bought it used, check for slack in the bearings and worn burrs? If those check out, I'd check the alignment of the burrs. Start by emptying the grinder, taking off the top collar and marking the bottom burr and top burr on the outer flat edge with a Sharpie or Marks-a-Lot. Install the top collar and with the grinder running, dial it down to its zero point (where the burrs touch). Take the top collar back off and look for even rubbing all the way around the burr.

Let us know what you find.

Bearings and burrs look OK and wear around the edge of the burrs looks even for the most part. There is a cm section that looks a touch less worn (sharpie) but it is hard to tell with the lighting.

My rule of thumb:

If it is a used grinder, it needs new burrs.

IMO the burrs shipped in the grinder still have a good 100lb or so quality grind left. Prior to shipping, after cleaning and doser sweep/snoz mods pulled nekkid shots no problem on the Linea at the Roastery. Sure different coffee, different basket, different espresso machine, different mano but same grinder.

If in doubt install the spare new burrs I also shipped.

The problem is (highly likely) your distribution technique not the grinder. IMO ditch the chopsticks, knitting needles what ever etc.! I've never used 'em at home going back well over a decade (b4 turning professional) and my first nekkid pull (with Rocky and Silvia) while scarry to be sure had no channeling no problem. Dose, quick Stockfleth's to level, tamp and pull end of story.

FWIW I never liked the stock Rancilio baskets and that first nekkid Rocky/Silvia pull of mine was not with one. Tried a few and settled on the 18g Synesso ridgeless which I still use today both at home and at our coffeehouses.

Thanks Mike. I don't think it is the equipment at all. You're a stand up guy and sold me an excellent grinder. What I can't understand is how the Rocky masked whatever technique issues that are surfacing with the SJ. The shots all up taste better and have way more crema, but I went from no channeling and sprites to consistent issues. The grind must be in the same ballpark so I don't know what is different. Well at least the shots taste better while I work this out.

Progress: this morning I put the triple basket in the naked pf and loaded 20+g of Belle. First shot ran fast and was the first sink shot I've poured in some time. Second was great: no channeling or sprites. Poured well, on time for volume and a set of tastes I've not yet experienced pouring this from my HQ 14g basket with 14g in it. I think I'll stick with the triple for a while as it is the dose klatch recommends and was my best espresso yet.

Try using a 17g or 18g dose in the HQ14 & see how it compares.