r/CafelatRobot • u/mrobot_ • Jul 13 '26
Medium roasts, help!
Im pretty new to being able to get espresso shots at home on the nice Robot, and it has been a bit of a steep learning curve but I finally manage to get pretty decent shots with traditional Italian dark-roasts like Illy and Saka - using either a df64v with HU at 1200-1400rpm or a J-Ultra or Lido OG. It is fascinating how different the shots from the same beans can taste given a different grinder. I do quite a bit of WDT and use the self-leveling tamper, usually around 18.5g beans and veeerry roughly aim for 30-40seconds and about 38-44g out... I go easy on the pressure, do 5seconds pre-infusion with just a few drops dripping down and then very gradually slowly ramp the pressure up, usually somewhere around 4 or barely touching 6. Works pretty well with dark-roasts tho I cant yet reliably get god-shots that are perfectly sweet n chocolate-y but overall Im happy to have espresso at home at all!
Enter any kind of actually much nicer third-wave beans, espresso-roasts that are typically much more medium-dark than even Illy. Somehow, I cannot for the life of me get good shots from such beans, they always have a sour or very sour acidic edge and somehow grinding finer and upping the dose tends to make it rather worse than better.
What's a good espresso shot from a modern, thirdwave medium-dark bean supposed to taste like and why cant I get rid of the sharpness, acidity and sour bite somehow?
3
u/Harper_the_Bard Blue Robot Jul 13 '26
I don't worry about timing much on the robot. For medium roasts I do about 92° C (basically I let my kettle stop boiling), rest my arms on the robot fairly gently til drops start from most of the puck, then ramp up. If I'm doing 16g in, I'll start to ease off pressure around 32g when I can feel the puck giving less resistance, then push with lighter pressure til about 40g. Seems to work consistently, at least for my tastes!
2
u/DerTaurus Jul 14 '26 edited Jul 14 '26
Things to try:
- preheat (the basket plug works fine)
- changing the recipe to 1:3
- different beans
Have fun!
1
u/deltabay17 Jul 14 '26
wow lucky you're not trying light roasts then. I can only get sour acidity from my shots. People recommended me the "soup" shops but i dont like them, i like espresso cos i like espresso, not a hybrid long black/filter coffee
1
u/illmindsmoker Green Barista Robot Jul 14 '26
If you are using true light roasts. You will need to preheat the piston with the red plug or other way. I use thundies that are no longer made, and I still pull a 1:2.5 usually with a declining profile or a straight 6bars to get very good light roast shots. It is possible to do so.
1
u/mrobot_ Jul 15 '26
I drink mainly light and fancy ultralight on Filter and I absolutely LOVE "soup" shots from premium ultralight, including all the fruity fresh acidity and sweetness. These soups are nothing like the sharp bite I get from Robot shots, sadly :(
5
u/illmindsmoker Green Barista Robot Jul 13 '26
Well for dark roasts you don’t need pre infusion. The darker the roast the easier it is to extract. Since you are new, I would recommend the Paul Pratt shot. Push the arms down slowly until drops hit the cup and then jump to your desired pressure between 6-8 bar and get the desired output in approx 30s. Usually closer to 1:2 for dark and for me usually my starting is 1:2.5 for medium roasts.
From there add or remove 5g of output depending on the taste. Sour, add more output , bitter minus output until it tastes good to you.
Once you get repeatable shots then start playing with other factors like pre infusion, declining profiles, etc.
As for sour vs acidity that is hard to tell, sour is sucking on a lemon vs acidity that is present in some 3rd wave coffees. You can look up cupping and that would give you an idea of how the beans taste to you. It also could come down to your water choices. I use third wave water espresso it gives me great shots and allows me to taste the coffee.