Help brewing with Cafelat Robot

A haven dedicated to manual espresso machine aficionados.
mbroder
Posts: 30
Joined: 1 year ago

#1: Post by mbroder »

Hi,

Here is my brew recipe using the Cafelat Robot and Kinu grinder.

-water: 99.5 degrees
-Dose: 16 grams in hoping for 32 grams out ( I also tried 17/34)
-timing: 5 second pre-infusion at 1 or 2 bars, then another 15 second pull at 6 bars, then 5 seconds of slowly winding to zero bar.
-Beans: dark roast (psychedelic sunrise by Disco Coffee) about 10 days from roast date

Using my Kinu grinder I tried various grind settings (I've tried several shots between 1.1-1.3 and 1.1.2 seems to get me the closest end weight unless I am way off due to channeling I am not seeing). Generally the shots are still coming out about 5-10 grams too heavy and taste terrible. I wanna say it is too bitter but I am too new to trust the difference between sour and bitter so I could be wrong. I try going finer but I get channeling. I tried going coarser but the water just runs right through the puck in no time.

pre-infusion looks good, I am not seeing channeling. the puck looks good when I dump it.

I am VERY new to all of this and I feel like hitting my head against a wall. Any advice would be appreciated.

cheers,

thirdcrackfourthwave
Posts: 572
Joined: 5 years ago

#2: Post by thirdcrackfourthwave »

A couple of caveats, I don't do a lot of dark roast stuff ( I got some over the holidays and passed of to DW) I 've never seen a Kinu live and in person. Typically I dose 17.5 and about 35 out--pretty sure this is not your problem as you have tried 17/34. So. . . .
1. Not sure you need a pre-infusion with dark roast, again probably not your problem. 2. You do need to figure out the difference between bitter and sour--it is the difference between under extraction and over extraction. Sour is citrus, bitter is cruciferous veggies or unsweetened chocolate, for example. 3. My pulls are generally longer--25-low 30s and at higher pressure. While I don't necessarily do much of a pre-infusion with darker stuff I do a gentle ramp up and hold the shot at around 8bar for all but the last 5 ish grams--which I decline to about 4 bar before ending the shot--all the ishes and ranges are because I am lazy and the Robot is very forgiving. 4. How the puck looks is irrelevant with a Robot. How the shot looks while being pulled is relevant. If I did what you did with the beans I generally use--not as dark apparently-- my shot would be under extracted--sour.

I would be inclined to updose your darker roast and grind finer, and/or maybe reduce your ratio to 1:1.5-1.75.

mbroder (original poster)
Posts: 30
Joined: 1 year ago

#3: Post by mbroder (original poster) »

Very helpful thank you! I am going to experiment under the assumption that my shots were underextracted. I am looking forward to trying again tomorrow.

No pre-infusion for dark roast...did not know that!

How long do you suggest I take to ramp up to 8 bar?

jgood
Posts: 903
Joined: 6 years ago

#4: Post by jgood »

mbroder wrote:Hi,

Generally the shots are still coming out about 5-10 grams too heavy and taste terrible.
Question: What do you mean by 5 - 10 grams too heavy?
I have Robot and Kinu and like dark roasts, but have you tried this roast before? I tend to preinfuse maybe 15 seconds, and pull at 9.5 or 10 bar, tapering down at the end. Total shot time from 1st drop, maybe 45 seconds or so. I go for a ratio of 20 gr coffee for 30 gr output. Very similar to what I do with the same beans and my e61/Niche setup.

mbroder (original poster)
Posts: 30
Joined: 1 year ago

#5: Post by mbroder (original poster) »

When I say 5-10 grams too heavy I mean I weigh 16 grams of coffee in the hopes the espresso weighs 32 grams but it ends up weighing 37 grams up to 42 grams ( so 5 or 10 grams too heavy). I am sticking to a 1:2 ratio.

I see you are deviating from what I understand to be the traditional recipe.... 1:2 ratio (I know this changes a bit based on dosage) and 20-30 second shot time. I am too new at this to understand why one would steer outside of this other than personal taste/preference and experimentation, but since I am new I am trying to start with a traditional cup. Perhaps with some beans this is just impossible and deviations are required?

You asked if I've tried this roast before. This is my first day making espresso. I can't believe how hard this is. I mean I knew it would be hard but I feel like an idiot wasting 8 cups today.

Ken5
Posts: 977
Joined: 4 years ago

#6: Post by Ken5 »

It takes a little while, so don't get discouraged.

Try to go longer than you are going for the actual pull. Pre infuse as you have been and then go for about 25 seconds for the actual pull and don't take 5 seconds to go to zero. It could be good to reduce pressure on the handles at the end if it starts to run faster, but I don't think it should be a 5 second ramp down to zero. See how this tastes and go from there.

What coffee are you using? Some are more sour and some are more bitter, some are more fruity and some more burnt, so choose wisely. There are coffees that I buy today that I just don't like, and in the beginning I probably would have blamed the tastes I was not enjoying on myself and not the roast.

jgood
Posts: 903
Joined: 6 years ago

#7: Post by jgood »

"When I say 5-10 grams too heavy I mean I weigh 16 grams of coffee in the hopes the espresso weighs 32 grams but it ends up weighing 37 grams up to 42 grams ( so 5 or 10 grams too heavy). I am sticking to a 1:2 ratio."

Why not stop the extraction when you get to your desired ratio -- get a small scale that fits under the cup and stop pushing on the handles when you are close to desired weight. (I think I use a "Joe Frex" scale for my Robot that's $20)

"I see you are deviating from what I understand to be the traditional recipe.... 1:2 ratio (I know this changes a bit based on dosage) and 20-30 second shot time. I am too new at this to understand why one would steer outside of this other than personal taste/preference and experimentation, but since I am new I am trying to start with a traditional cup. Perhaps with some beans this is just impossible and deviations are required?"

I prefer something extracted more like a ristretto. It's a tradition as well. YMMV or taste may vary.

"You asked if I've tried this roast before. This is my first day making espresso. I can't believe how hard this is. I mean I knew it would be hard but I feel like an idiot wasting 8 cups today"
What I meant to ask is - have you tried and liked this bean at a favorite coffee joint? I would find a place where you like the espresso (or cappuccino if that's what you're making -- you'd need a Bellman steamer for that) and then buy their beans. Be aware many shops sell various beans so ask what they're using for what you like. And if they are extracting 1:2 or whatever. That way you'll be aiming for something that you like. Otherwise you can't really tell if it's technique, equipment, or the beans.

And it does take a while to get dialed in with what you like. So don't lose heart. BTW it just occurred to me that the manual Robot may be harder to master than an E61 -- there are more variables. Coming from making espresso on various
E61 and commercial machines the Robot seemed easy to master -- but I knew what I was trying to emulate. BTW if you're not using the bottomless version of the portafilter (ie with the spouts removed) do so. It's a good diagnostic tool to know if your puck prep is good -- in which case the coffee rapidly forms a single stream. If you look at some videos you'll get an idea of what this should look like.

jgood
Posts: 903
Joined: 6 years ago

#8: Post by jgood »

Duplicate -- ignore

mbroder (original poster)
Posts: 30
Joined: 1 year ago

#9: Post by mbroder (original poster) »




My niche zero came in yesterday (heard kinu's all have different zeroes/starting points so perhaps this will be easier to determine if grind size is the issue).

New Recipe:
-Niche grind size 15
-water: 99.5 degrees
-Dose: 18 grams in hoping for 36 grams out
-timing: 30 seconds at 9 bar (no-pre infusion)
-Beans: dark roast (psychedelic sunrise by Disco Coffee) about 10 days from roast date

The shot was spot on in terms of the recipe above except the end cup was .7 grams over target weight and it took closer to 26 seconds to reach. I wish I knew sour from bitter but it tastes pretty bad. Here is the kicker. I had this bean as an espresso at a local shop and it was not good. I only chose it because it tastes great as a pressed coffee, and I was hoping that this shop did not know how to make a good espresso. When I had it as an espresso at my local shop it tasted pretty much like it tasted just now.

Can you tell from the pic if this is over or under extracted? (Note the glass is large)

At this point I am thinking of putting some research time into finding the right bean and hoping for better results.

Side note, I live in a DC suburb and when I went to DC to try a bunch of espresso (just walked around and stopped at random places) I did not like any of the shots I had. I would not characterize any of them as having any subtle notes of "sweetness." I have had good espresso from those fully automated machines and also those machines that have everything in one (like a dual broiler machine with a built in grinder) but I do not recall the beans used.

Jonk
Posts: 2210
Joined: 4 years ago

#10: Post by Jonk »

mbroder wrote:At this point I am thinking of putting some research time into finding the right bean and hoping for better results.
This. It's the most important starting point. You have a good grinder and machine, now shop around for beans that you like. It'll make everything else easy.

That said, if you don't like regular café espresso perhaps you can try pulling longer shots (try double the output to emulate superautos) or add a splash of water to the shot. Could be just down to personal preference, especially if you're not used to 'real' espresso