Having trouble with Cafelat Robot - Page 5

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Starguru (original poster)
Posts: 79
Joined: 9 months ago

#41: Post by Starguru (original poster) »

Just pulled my last shot for today, same routine as above, although at 155um instead of 150, although the coffee was a different dark roast (decaf this time).

I followed the advice above and tamped less hard, basically until the coffee just stopped compressing. I also put the basket on the top of the kettle while the water heated.

I noticed the pre infusion I only got about 2 grams in 10 seconds. The preinfusion looked nice and even though, like the beauty shots we sometimes see on Reddit.

I then went to 8 bars, down to 2-4 for the last 10g or so. Same ratio about 42:18. The flow from the bottom looked much more even; when I grind finer the coffee doesn't emerge evenly. Still not perfect. Ramping down the pressure after 30g of coffee are in the cup seems to have eliminated the channeling vortex Ive seen in previous shots.

Much more intense flavor. More bitter/smokey too. Im curious, should espresso have that bitterness, or is it really up to the barista what they want?

Also, I really wish there was a sticker I could by to put on the perimeter of the gauge so I could more easily see the damn pressure.

DSUK69
Posts: 7
Joined: 4 years ago

#42: Post by DSUK69 replying to Starguru »

If I was pulling dark roast, here is the recipe that I would do to achive smooth shots and avoid bitterness and smoky flavour

- No preheat, water temp ~95°C or less
- Slowly straight to 8 bar without pre-infusion or just very quick pre-inf after the pressure peaks at 8 bar, I then taper down to 3-4 bar
- Shot lasts about 15-25 second depending on the ratio
- Ratio 1:1 or 1:1.5 max (18 in 18 out or 18 in 27out), I would never exceed 30g out for dark roast

sympa
Posts: 135
Joined: 1 year ago

#43: Post by sympa »

Your routine looks great. But one note on heat management. For dark roasts, ignore preheating, as the machine will brew in the 80s (C) and that's fine for that roast level. But for light roasts, brewing in the 80s is no good, and just putting your basket on the kettle is not sufficient. The problem (also feature) of the Robot is the piston: a big hunk of metal that acts like a heat sink. You need to preheat the piston by perching a cup of boiled water underneath it. Doing so will get your brew temp to around 90C and hold it steady throughout the brew (again, because it's a big chunk of metal, it retains heat well). To get your brew temp up to 95C or so, you'll need to preheat the basket, and for that the best method is the "double pour". Hold your already prepared basket (loaded with tamped coffee + filters) over your sink and basically overfill your basket. That'll heat up all the metal (and it doesn't make a mess or disturb your coffee bed).

So for me:
light roast: preheat piston + basket
medium: preheat piston
dark: no preheat

User avatar
Jeff
Team HB
Posts: 6923
Joined: 19 years ago

#44: Post by Jeff »

Decaf coffees are hard. Even the best of them pull very differently. They often "break down" quickly during extraction and also benefit from a different grind.

Unproven, but I can believe that a producer isn't going to run their first-rate beans through decaffeination.

Coffee "just is" bitter. How bitter depends a lot on how darkly roasted it is. Even at a very dark roast level, the best roasters can strike a good balance between bitterness, acidity, and flavors perceived as sweet. As you get comfortable with your new machine, you may find which roasters and blends you enjoy more than others. Just because somebody else says it a given coffee is great doesn't mean that you're gonna like it.

Starguru (original poster)
Posts: 79
Joined: 9 months ago

#45: Post by Starguru (original poster) »

sympa wrote:Your routine looks great. But one note on heat management. For dark roasts, ignore preheating, as the machine will brew in the 80s (C) and that's fine for that roast level. But for light roasts, brewing in the 80s is no good, and just putting your basket on the kettle is not sufficient. The problem (also feature) of the Robot is the piston: a big hunk of metal that acts like a heat sink. You need to preheat the piston by perching a cup of boiled water underneath it. Doing so will get your brew temp to around 90C and hold it steady throughout the brew (again, because it's a big chunk of metal, it retains heat well). To get your brew temp up to 95C or so, you'll need to preheat the basket, and for that the best method is the "double pour". Hold your already prepared basket (loaded with tamped coffee + filters) over your sink and basically overfill your basket. That'll heat up all the metal (and it doesn't make a mess or disturb your coffee bed).

So for me:
light roast: preheat piston + basket
medium: preheat piston
dark: no preheat
You are saying to preheat the piston soak it in boiling water, and the get the basket extra toasty just overfill the prepared basket/portafilter so it spill in the sink?

Jonk
Posts: 2216
Joined: 4 years ago

#46: Post by Jonk »

Starguru wrote:just overfill the prepared basket/portafilter so it spill in the sink?
That's what I do. Tilt it away from your hand :!: and make sure you leave about 3mm of space for the piston once you're done.

sympa
Posts: 135
Joined: 1 year ago

#47: Post by sympa »

Yep.