Here is my latest report to Sean at Caffe Lusso. I'd be interested if anyone may have a solution to my uneven extraction problems?
I keep working to dial in GMC on my machine. I'm still having difficulty. My main problem is that I can't get a nice, even extraction, no matter how much care I put into puck preparation. The flow I get from the bottomless pf is always somewhat uneven, often channels, and the resulting flow is thin, almost watery, and clings to the bottom of the basket (as opposed to flowing out in a nice cone).
This is despite stirring the grounds to break up clumps, distributing evenly in the basket, and tamping evenly with a level of care that even exceeds what I usually put in with other blends or s.o. beans, and from which I'm used to nice, even extraction as the norm.
It has been a while since I had last pulled GMC, but I don't recall it having been fickle at all.
Right now, the resulting beverage doesn't have an offensive taste per second, but it has very little body or viscosity, and none of the velvety feel I recall from past experience with GMC.
Have you sometimes seen this phenomenon, and if so would you have any suggestions for a fix?
I'm currently putting 17 g in an 18g VST (to ensure that interference from the screen isn't the cause of the channeling) and get 27g out in 25-27 secs at around 203 F, albeit with some channeling and unevenness as described above.