Jonk wrote:It's the second time I've read these kinds of comments. Doesn't make sense to me. If the shot chokes, you should be able to achieve a lot of pressure (not that it's recommended..) and 8 bars should be the same amount of strain regardless.

My favourite strategy with dark roasts is to grind fairly coarse and go for a brief pre-infusion or none at all. I'm guessing that's a good idea with the grinder you're using (at least with my K-Max it seems coarser and faster is preferable). If you're not used to drinking espresso, I'd suggest increasing the ratio to 1:3-4 even though you're using a dark roast (or dilute with a small amount of water afterwards).

I might be describing it wrong then. It choked it enough to where I felt like I had to lean on the machine to get anything out and anything past four bars just felt like I hit a brick wall.

I'll definitely try grinding a bit coarser and hitting it a bit faster.

I like the idea of tilting the gauge upward so I can see it. I was having to lean down to see the gauge and using mostly wrist and forearm strength instead of leaning into it because of that. That would make it a lot easier to see

wormraper wrote: I might be describing it wrong then. It choked it enough to where I felt like I had to lean on the machine to get anything out and anything past four bars just felt like I hit a brick wall.

Like Jon I don't understand this. The force to reach 8bar or whatever doesn't change when the flow rate is zero. It's the same.

jpender wrote:Like Jon I don't understand this. The force to reach 8bar or whatever doesn't change when the flow rate is zero. It's the same.

I'm guessing I subconsciously backed off because it felt like I'd break something if I pushed harder

Are you a 400 lb sumo wrestler? If not, the greater risk is that if you push too hard, beyond the limit of control, you may cause the machine to slip and hit you somewhere you really don't want to be hit. BTW, I've found the sweet spot for pressure on a Robot to usually hover about 6 bar, all other things being equal.

BTW, you are correct in choosing a darker roast for learning the ins and outs of a new machine like a Robot. Lighter roasts that like higher water temperatures are going to be inherently more challenging on the Robot. But here's a suggestion: I know there are a number of good roasters around Tucson -- I lived in Phoenix for a time back when and knew a few Tucson-based coffee nerds -- so visit a few shops and have them pull you darkish-beaned espresso shots. While some of them won't be to your taste, you'll probably find some you like, in which case get some of their beans to work with, having experienced what a good shot should taste like with that particular blend.

One other thought: a new grinder might be a little misaligned, which would make it very difficult to get an evenly-extracted shot. Might want to confirm the consistency of the grounds (at espresso settings) you're getting out of it...

Jonk wrote:I can relate to that explanation. The difference being that there's no motion in the levers.

What's nice with the instant feedback of manual levers (plus bottomless portafiler) is that you can adjust the shot way before hitting the brick wall and even if you do - back off slowly almost all the way to zero and apply new pressure for a smoother shot. If you notice in time, prolong the pre-infusion at very low pressure until you've got beads forming from all the holes in the basket before applying more pressure.

hahah, yeah I wrench my own motorcycles and my instinct when something stops moving and hits a hard wall is to STOP immediately and that was hard to overcome

I made a 5th one for the day and it turned out rather well. I dialed it back ONE notch coarser, did a 17 gram load, 34 gram output and flipped the robot around so I could lean OVER the robot and look down the other side at the gauge so I didn't have to keep leaning over in front. did a 5 scond PI, roughtly 20 second pull at a hard CONSISTENT 8 bars (amazing what you can do when you can see the gauge the whole time) and it wasn't bad. I'd say starbucks level. I could get some roastiness and the harsh solventy taste was heavily diminished. Not perfect by any means but I've only pulled 5 shots my very first day. This is rather fun

Balthazar_B wrote:Are you a 400 lb sumo wrestler? If not, the greater risk is that if you push too hard, beyond the limit of control, you may cause the machine to slip and hit you somewhere you really don't want to be hit. BTW, I've found the sweet spot for pressure on a Robot to usually hover about 6 bar, all other things being equal.

BTW, you are correct in choosing a darker roast for learning the ins and outs of a new machine like a Robot. Lighter roasts that like higher water temperatures are going to be inherently more challenging on the Robot. But here's a suggestion: I know there are a number of good roasters around Tucson -- I lived in Phoenix for a time back when and knew a few Tucson-based coffee nerds -- so visit a few shops and have them pull you darkish-beaned espresso shots. While some of them won't be to your taste, you'll probably find some you like, in which case get some of their beans to work with, having experienced what a good shot should taste like with that particular blend.

One other thought: a new grinder might be a little misaligned, which would make it very difficult to get an evenly-extracted shot. Might want to confirm the consistency of the grounds (at espresso settings) you're getting out of it...

lol, yeah as I said in another post, I wrench my own bikes and instincts are when you hit a hard wall to NOT muscle through it and that was hard to overcome.

phx does have some nice beans. Tucson does too, I used Savaya's epsresso blend. I did a 5th shot that turned out much better this go around employing some of the suggestions here. I'll try the 6 bar pressure next and see if that does anything.

and thanks for all of the helpful tips. I'm finely attuned to filter coffee and can adjust for and taste a million different variables like a true coffee snob, but for me espresso was just lattes so I'm feeling like I have to re-learn coffee all over again

I'm kind of an outlier around here because I strongly prefer dark, old school roasts.
I also do long pre-infusions and and press pretty lightly when it comes time to hammer down.
You'll find your way soon, just keep experimenting and change one thing at a time.

As you discovered you needed to grind coarser. There's a "peak" in extraction as you go finer. It's called volcano effect, the extraction is higher as you go finer until a point where it decreases again because the particles are too packed and you get channeling, creating both bitterness from the overextracted parts of the puck and sourness from the dry-ish underextracted parts with less water flow. Also fresh coffee has a lot of CO2 the first 10 days from roast, and this gas limits water contacts with the particles, again lowering extraction. The Robot has a temperature stability problem, which is a problem only for light roasts (it's better to also preheat the piston in that case), but with darker roasts you should absolutely have no problems once you nail the grind setting and using rested coffee (also the grind setting will need to change day by day as the coffee ages, that's just life )