Still new around here. Watched the James Hoffman videos on dialling coffee, bought a blend coffee (Grumpy Momentum) - 3 tries and I had it pretty dialled in. Refined things a bit over the next few days - great espresso for breakfast and reenergizing between meetings. Then that bag ran out

Next bag is a Honduran single source, and it seems to me it's a lighter roast. After a few ridiculously fast/runny extractions, I'm going pretty fine grind - to the point where the grinder at times seems to not "catch" any beans (or something else is happening), and I'm getting a bitter coffee, tiny layer of crema. 14g->30g, 90-95C grouphead temp, tamping heavily.

I've probably done more than 5 shots so far, and no luck. Any advise? (don't buy that coffee again! )

I don't know how light your "light" is, but medium-light to light roasts (Passenger, George Howell's and Onyx light roasts, La Cabra, Tim Wendelboe) usually produce virtually no crema.

"El Salvador & Guatemala, Malted Milk Chocolate, Caramel, Orange Zest" for Grumpy Momentum suggests to me a medium roast (relatively sweet or "un-heavy" chocolate flavors, just a hint of fruit, no florals)

LAS MARIPOSAS
HONDURAS
El Cielito, Santa Bárbara
Golden Raisin, Orange Zest, Praline, Jasmine

suggests to me a medium or perhaps medium-light roast. I don't know Grumpy's style or if this is the Honduran you have.

Different beans can require different grinds, depending on the "species" of coffee, where it has been grown, and how it has been processed and then later roasted. It is not uncommon for me to find that a medium-light or light roast starts to taste balanced somewhere in the 1:2.5 to 1:3 range (for me, 17 g in, 42-52 g out). It may be that you're tasting sour and not bitter at your roughly 1:2 ratio.

Lighter roasted beans tend to be harder than the same bean roasted darker. It is possible that the Notte doesn't have the burr geometry and power to cut through harder beans. I don't recall any complaints about that, so it may just be that it will take longer to grind (which is the case on most grinders).

Tamping harder doesn't really slow down the flow meaningfully. 8 bar is over 100 PSI and a 58 mm basket is about 4 sq. in., so unless you're the proverbial elephant in the room or the Samsonite gorilla, when that water hits the top of the puck, the difference between 15 and 50 pounds of tamping force isn't going to matter a lot (once your past the point of ensuring the puck holds together as the pressure is applied). Edit: A 47 mm basket is around 2.7 sq. in.

I'm far from an expert on the La Pavoni techniques, but there may be some hints in the Levers section on pulling lighter roasts when them.

Thank you for the kind advise!

The Grumpy coffee is "Honduras / Las Flores" - https://cafegrumpy.com/las-flores-bulk- ... escription - on the bag it says "juicy cup with notes of mango, apricot, brown sugar, nutmeg".

I managed to get a grind a few steps finer from my Notte. The extraction was an unholy mess due to channeling. I guess at this fine grind I do have to work more on my puck prep.

I'm surprised to learn that I should explore going _longer_ on the ratio. I thought it'd end up burned. I'm not sophisticated on my tasting so sour might well be.

Tomorrow I'll keep exploring on this fine grind, better puck prep and longer ratios.

Sour/bitter still confuses me, even after thousands of shots.

It's hard (impossible?) to burn coffee during extraction. With a darker roast, what sometimes happens is that the longer shots will start to extract the bitterness from the roasting process. With a well-roasted medium or lighter, there aren't anywhere as many of those flavors to extract. While the shot may become less tasty (unbalanced or thin or ...) with a longer extraction, it seldom gets those "burnt" flavors.