I've been soaking up knowledge from these forums for months now, absolutely invaluable. This is my first post so please be gentle! And I apologise for the length.

...[edited down the the core question]...

I think I'm having trouble dialing in my Cimbali, and want to rule out a grinder/burrs issue so I can focus on my technique.

My set-up at work: Nemox Junior & Cimbali Junior I picked up last week for next to nothing.


I'm grinding from my Cimbali into a cup on 0.1gm scales, then giving it a really good stir before spooning into the basket.

Here are a few details.
I'm extracting long enough to pull a double (50-60ml) shot.

A) dose:16.1mg, grind:6.75, extr. time:60seconds!
Expected it to taste over-extracted and bitter but if anything it was a little sour and weak.

B) dose:17mg, grind:7.0, extr. time:35seconds
Upped the dose and went a little coarser to try and pull the time down. Again no kick to it at all.

C) dose:17mg, grind:6.75, extr. time:55seconds!
Kept the dose the same (17gm gives me a little clearance between puck and screen, post expansion the puck has compressed against the screen). Again I expected C to be over extracted and bitter, but no, the sourness had gone but still no real kick.

I know my Nemox runs a little cold, the shots from my VBM Domobar Jnr HX at home are way way hotter.
I've never played with the temperature in the past, and before I got the Cimbali I had a dirt cheap Breville. Sure it was incapable of grinding anywhere near fine enough, however I was generally able to squeeze a good strong shot by overdosing to the max - 21gm+ and hand-stand tamping so I could force the portafilter on.

I'm not sure what to try next. I know it's very early to be considering a problem with the grinder, it's just that it was disgustingly clogged and when I got it, I stripped it right down and had to soak and scrub the burrs. They almost looked rusty so I took to them with a wire brush. In the end everything was nice and clean, just can't help wonder if I damaged the burrs (or they were already stuffed).

Andrew_NZ wrote:I know my Nemox runs a little cold, the shots from my VBM Domobar Jnr HX at home are way way hotter.

Have you tried running up the temp using the steam setting before pulling the shot?

OK, I'll give that a try to see what effect it has.

Generally I try and change as few variables as possible. As I've never temp surfed in the past and pulled decent strong shots I was looking at new/changed variables... basically grind, dose & tamp, then starting to wonder about the physical grinder or burrs.

For about a month (this is at home rather than work) I had my Mini Mazzer running with my old Nemox, eventually I got the 2 of them working together nicely. Now it's Mazzer + new VBM Domobar Jnr HX... my home coffee has certainly moved up to the next level.

Your extraction times point to a pressure problem. Whether or not you're getting espresso is arguable.

BDL

False alarm on the brew temperature, turns out there is a huge 60 Fahrenheit difference between my home and work milk thermometers!!

I'm not so sure pressure is the issue. My figures were not as accurate as they could have been.
Also I've been pulling very respectable shots from this machine for months with my cheap Breville grinder, far better (richer/stronger) than any of the cafes around here.

Here are the current figures:


I bumped the dose up to 18gm on the last one.

What seems to be happening is that there is a long pause before anything appears in the cup, about 20seconds, from there on the flow and look of the shot in the cup are bang on. After 20 seconds it starts with a few slow drips and slowly increases into a steady 'mouse tail' stream.

60 seconds (20 nothing, 40 with flow) to pull approx 40gm just seems too long. And the resulting shot is mild rather than intense.

NOTE - I've running 2 Nemox machines for years with sub-standard grinders, way too coarse. The shot time and flows were never anywhere near the norms. However, by super overdosing and tamping I have generally managed to pull nice rich shots.

When I cleaned up the Cimbali and got started the other day I expected to pull a few black tar like shots while dialing in. I just can't understand why everything so far has been mild, quite drinkable just not the super kick I'm always striving for. I'm tempted to bring my mazzer into work and see what happens.

I seem to be making some progress. I took the Cimbali home over the weekend and ran it beside my Mini Mazzer and Domobar Jnr, it performed very well so I'm confident there is no issue with the grinder.

I'm wondering if my Nemox is quite picky about its dose, preferring a generous overdose. To the point where I need to go quite coarse on the grind so I can dose high enough to keep my extract time within the norms.

As mentioned, I've been pulling decent shots from Nemox machines for years, in the past sub-standard grinders forced me into a coarse grind 21gram handstand tamp.

This morning I went a couple of clicks coarser and upped the dose to 18.5gm, and pulled a 40gm shot in 45 seconds. Finally the shot started to shine through the 3-4oz of textured milk.

Second shot... went a click finer and dropped the dose back to 17.5gm, pulled 37gm in 35seconds. The flavour and punch had dropped away again!

I think I'm going to push the dose up to the point it just nudges the shower screen when I engage the portafilter, then play with the grind from there.

Despite using the WDT + very carefully chopping and leveling with a bamboo skewer I wonder if channeling has caused the weak extracts?

The odd thing is the flow and colour of the extracts have looked mouthwateringly excellent, just flat and lifeless on the tongue.