Extraction of light roasted beans with Cafelat Robot

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Juniorcoffeelover22

#1: Post by Juniorcoffeelover22 »

Hello everyone

I'm using the Robot for a while now, and I find it somewhat hard to extract the full and complexed flavors from a light roast beans I have. The grinder I use is 1Zpresso JX-PRO.
I looked in the web for help and I found two methods but neither of them supplied the result I wished for. The recipe I've tried was to grind finer (grinder in the second method) aiming to choke the Robot, put the grounded coffee in and tamp, boil water, put it in to warm everything up, throw the water and add new just-boiled water and extract quicky as you can on something like 7 bars.
It sounds logically attractive to try the mentioned recipe, because if the beans grounded finer, the bigger surface area between the water and the grounded beans and the more flavors will extract.
But! the taste is not as it was when I drank the espresso of the same beans at the coffeehouse. I can't replicate/get almost the same complexed flavor I felt. I feel a bitter taste which is my indicator for failing in extraction. This beans are blend of Colombian, Uganda and Costa-Rica light roast and the taste is godly good fruity and acidic.
Only yesterday I found out that it is a struggle to extract the full flavor of light roasted beans and it is suck because I now know how tasty it is.

I feel like I'm overwhelming you, and you get my point, please help with tips and tricks? Is there anything to improve it? How can I extract the most flavors from the beans?

thanks :)

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Nate42

#2: Post by Nate42 »

Extracting very light espresso is challenging. Your grinder unfortunately may not be up to the task of replicating the results of the coffee house. However that doesn't mean you should give up.

You are on the right track with pre-heating, most light coffees benefit from a higher temperature. However, if you are noticing bitterness it might be worth a try at a lower temperature.

With the robot you can do a long pre-infusion and slow ramp up, which allows you to get away with finer grinds. You can also reduce dose and or increase output to improve extraction.

Another thing to keep in mind when dialing in, is a finer grind is generally better, until its not. If you are already too fine to start with, it can be non-obvious which direction to move. So it can be useful to err on the side of slightly too coarse initially, and dial in from there.

ojt

#3: Post by ojt »

Not an expert on the matter but I think with the Robot your main worry would be brew temperature. I think the grinder should be up to the task even if it wouldn't yield the exact same taste profile as at the shop.
Osku

Juniorcoffeelover22 (original poster)

#4: Post by Juniorcoffeelover22 (original poster) »

Nate42 wrote:Extracting very light espresso is challenging. Your grinder unfortunately may not be up to the task of replicating the results of the coffee house. However that doesn't mean you should give up.

You are on the right track with pre-heating, most light coffees benefit from a higher temperature. However, if you are noticing bitterness it might be worth a try at a lower temperature.

With the robot you can do a long pre-infusion and slow ramp up, which allows you to get away with finer grinds. You can also reduce dose and or increase output to improve extraction.

Another thing to keep in mind when dialing in, is a finer grind is generally better, until its not. If you are already too fine to start with, it can be non-obvious which direction to move. So it can be useful to err on the side of slightly too coarse initially, and dial in from there.
ojt wrote: Not an expert on the matter but I think with the Robot your main worry would be brew temperature. I think the grinder should be up to the task even if it wouldn't yield the exact same taste profile as at the shop.
Thank youu for your answers.
Actually the 1Zpresso JX pro is excellent grinder, are you familiar with it? It can grind very good and precise. How long should I go with pre-infusion in your opinion, and how long should all the process be?
By the way, can you explain to me how increasing output improve extraction? I don't seem to understand it.

K7

#5: Post by K7 »

In my experience, not all light roasts benefit from higher temperature. Delicate notes can get lost and you get bright bitter notes (not the dark bitter notes from roasting or from overly long extraction). Preheated basket and off-boil water get you very high initial water temp like 95-96C so that may be hurting in your case. You might want to try little to no basket preheat + off-boil water which will get you ~91-92C initial temp and but do preheat the piston and PF so the temp decline is more moderate. If you still get bright bitter notes, you can go even lower with cooler water (e.g. 96C from temp controlled kettle or let it sit for a minute or so after boil). That's what I do with some light roasts.

It may also be the grind not being fine enough.

Juniorcoffeelover22 (original poster)

#6: Post by Juniorcoffeelover22 (original poster) » replying to K7 »

Thanks!
I forgot to mention important thing - When I was at the coffeehouse and drank the espresso, it was very hot even boiling. So I assume that high temp. is fine with this beans?

K7

#7: Post by K7 »

Never seen or heard of espresso served so hot to the point of boiling..
Maybe you can ask them how they pull (dose, temp, time).

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Nate42

#8: Post by Nate42 »

Juniorcoffeelover22 wrote:Thank youu for your answers.
Actually the 1Zpresso JX pro is excellent grinder, are you familiar with it?
I don't have personal experience with that grinder, but I can see it's hand grinder with a medium size burr. I'm not bagging on it, but uber expensive large flats are all the rage for getting the most out of light espresso. I'm going to guess your coffee shop is using a large flat or large conical. Not trying to discourage you though I'm sure you can improve your results.
Juniorcoffeelover22 wrote: How long should I go with pre-infusion in your opinion, and how long should all the process be?
It depends on the coffee. I would consider a "long" preinfusion to be in the 10-20 second range. With a preinfusion that long, shot time of a minute or slightly more would not be unreasonable. Probably don't want to go much longer than that.
Juniorcoffeelover22 wrote:By the way, can you explain to me how increasing output improve extraction? I don't seem to understand it.
The more water you flow through, the more opportunity you have to extract the good stuff from your coffee. This of course also makes the resulting drink weaker, but that's also potentially a good thing. We interpret very strong flavors as "bitter". Some dilution can make it easier to taste the true flavor profile.

Jonk

#9: Post by Jonk »

K7 wrote:You might want to try little to no basket preheat + off-boil water which will get you ~91-92C initial temp and but do preheat the piston and PF so the temp decline is more moderate.
I agree with this and it has become my regular routine to just preheat the piston and use off-boil water with cool basket and portafilter, no overflow. Some light roasts seem just as sensitive to high temperatures as medium roasts and not doing anything excessive is usually a safer bet in my experience. It's also more convenient as long as you've found a good container to preheat the piston.

I'm thinking the cafe is just serving their drinks in very hot cups.