Ive started to dial in the Luna Bermudez beans. Long pre infusions seem to give a muddier cup if the grind is fine enough to peak at 6 bars of pressure after the infusion period. If the grind is left coarse, and the pre infusion is circa 20-30 seconds long, 3 bars of pressure is around the peak and the resulting espresso comes out like a filter brew (which is actually quite enjoyable, heh).

I'm currently toying with a variation of Joe D's extractamundo profile: a quick ramp to 7 bars, then a bloom period lasting 5 seconds, followed by a quick ramp and pull to desired volume. I'm still adjusting ratio to see what I can get from it.

Hey, good feedback. I have experienced similar results although I have no idea what pressures I hit.

You should try a small dose of around 13.5g of the Luna in the small basket and pull the shot on the quicker side.

Yeah, I'm currently pulling this as a turbo shot with 14g in the basket. Will play around a bit with dose.

The info in this post helped me out quite a bit for light roasts. Just pulled the best shot I've had so far on the CT2:

User Experience with the Strietman CT2

To get shot times that long, I realized I'd need to grind even finer than the range I was using before and had deemed muddy. After reading the post linked above, I decided to go 35um finer, and the shots carried intensity without the muddiness I was getting 20um higher. In any case, it's a 15s-25s-40s pull (1m25s total), peaking around 6 bars at the start of the 45 second phase. The actual flow rate is a steady trickle, with the pressure declining accordingly. Im probably down to 3-4 bars for most of the shot. Super clean, bright acidity and fruit flavor, with a lingering finish. Exceptional...

Wow I need to give it a try. I haven't tried anything nearly that long. Typically the SLM burrs in the MAX extract pretty quickly but it's definitely worth a shot.

What burrs are you using?

Thanks for the feedback. How was the Luna?

I'm using a Bentwood V63. It has unimodal 63mm flat burrs. Probably doesn't extract quite as quickly as what you have there. That said, slow and long pulls arent usually associated with ultra-high extraction rates, so it usually balances out.

The Luna is interesting as both espresso and filter. Worth a shot if you like illegal light roasts, heh.

Oh yeah, you already mentioned the Bentwood. Sorry! I love the grind adjustment on that machine!

No worries. Yeah, it's super easy to change between filter and espresso ranges.

Just pulled another great espresso shot with the Luna. Hit all three of the tasting notes.

At what micron setting are you on the bentwood?

Also are you using 16g doses in 18g basket? With extractamundo profile?

Right now, I'm using 16g in the 18g basket, for a three-phase 15/25/45-second pull. Grind range is 95 to 110 um from burr touch, depending on whether I want to play with a sharper decline from 6 bar.

For extractamundo, grind range was 125 um from burr touch, using a 13.5g dose in the 15g basket. I didn't try extractamundo with the 18g basket - no particular reason for that other than moving onto the longer shot style.