How do you decide if something tastes sour, vs. bitter, vs. too aggressive?

The sticky Espresso 101: How to Adjust Dose and Grind Setting by Taste has a handy chart for adjusting the variables based on flavor. Before adding milk I tasted this morning's shot to see where it fell in this chart. I'm pretty sure the grind was a major click too fine for the dose and brew ratio because the flow was so slow/dark initially. But honestly, I could not decide by taste if the flavor was bitter, sour, or too aggressive. Any of those 3 terms seem appropriate. I do not mean that in the nuanced sense of having both sour and bitter flavors (e.g. from a non-uniform grind). I'm just not sure what it was I was tasting.

Fortunately, if adding milk and a touch of sugar works to mask even the most awful, burnt corporate coffee, it was more than sufficient to smooth out my own imperfections.

Drop the temp down 5 degrees if you are able to. Had my first sour the other day (I dropped a lot more than 5) when I couldn't tell if I was pulling consistent bitter or sour (I knew and figured it was all bitter) this shot help me so now I Def know what a bitter or sour shot is.

I'm still figuring out difference from aggressive or bitter myself.

Scratch aggressive for now and just think bitter and sour. Basically those are the two ends of the scale you want to balance. I fought with this for a long time after starting and just recently became able to make the distinction. One thing I notice is that bitter seems to hang around on the edges of your tongue a while after the sip is gone. Sour is more like a quick off putting tatse and is fleeting.

Also see this.

https://baristahustle.com/coffee-extrac ... -taste-it/

I found it most helpful to purposely consume coffee on each end of the spectrum (under and over extracting a shot). Even to the untrained and currently refining palate, like myself, the difference between each should be easily discernable.

Then you can work through the finer points of differentiation, also making sure to consider the actual taste profile of the individual coffee being consumed (as indicated by the roaster, for instance).

Happy tasting!

It might help to think of foods that are sour vs bitter. You would think of a lemon as sour, but not bitter. You might think of dark chocolate as bitter, but not sour. It is easy to miss the difference at first, but I found putting it in that context helped when I was trying to develop a palate (which I think is the hardest skill in being a good barista - more subtle than the mechanics of pulling good shots). I agree with the commenters above that the sour bitter distinction is more important to understand than adding the word aggressive in.

DavidO wrote:I found it most helpful to purposely consume coffee on each end of the spectrum (under and over extracting a shot). Even to the untrained and currently refining palate, like myself, the difference between each should be easily discernable.

Then you can work through the finer points of differentiation, also making sure to consider the actual taste profile of the individual coffee being consumed (as indicated by the roaster, for instance).

Happy tasting!

Totally agree it helps to taste extremes very early on. It actually becomes harder to decipher sour/bitter as you get closer to a good extraction though.

One thing I found helpful was letting it sit for a while, or pouring it out and smelling the residue. It will definitely help identify any bitters, sour is mostly taste though

Stir the espresso and let it cool a bit. Your tongue will work better when it is cooled below normal serving temperature. Professional cupping does a lot of tasting when the sample is well cooled.

As an experiment setup three espresso cups under your portafilter and pull a nice slow shot. Put the first cup under for the first few drops, say 5-10 seconds worth. Then move it out and put the second cup in and capture the next 1/3rd of the shot. Then move it out and put the last cup in and let it run a bit long and stop.

Then taste each part of the pull. The first few drops are usually strong and sour. The middle will usually be a bit more balanced and the last will have more of the astringent qualities and bitterness from the end of extraction.

You can do the experiment many different ways, like grind too coarse and run a short fast shot and experience sour. Or a low dose gorund fine and let the shot pull for an extended time to taste over extraction.

The science of this gets easier with tools, like a refractometer, so you can measure absolute changes and then taste them to see how they change the flavor.

Completely agree with this!

And parenthetically I will add my experience on sour v bitter. I have experienced sour shots that simply would not leave my sense of taste for hours. Bitter dissipates more readily, or maybe it didn't get it bitter enough. I have no idea what aggressive is - makes as much sense to say this as, "the shot had hints of mauve with taupe over tones."

Bland vs Aggressive: It is difficult to make a judgement one way or another until you have a balanced shot. Once the shot is balanced you can judge its blandness / aggressiveness range.

Bland I think is an easy one to figure out, you get the shot balanced and it tastes boring, like it is failing to live up to its potential.

To me, aggressive is when you have the shot balanced, yet it is still unpleasantly harsh for some reason. This could be that you taste a lot of good notes but there are still some bad ones shining through you don't like, or that the shot itself tastes rather good but the aftertaste starts to get off-putting very quickly.

the "Rule of Thirds" experiment as described by nuketopia is a great exercise for learning to determine sour vs bitter.
When I did it I took inspiration from the "schechtermatic cupping device" and put three espresso glasses on a dessert plate and then slid them across the drip tray while pulling the shot.
Another good read: Balance in Espresso is Intense Bitter and Sour Cancelling Each Other Out
I had the "pleasure" of participating in Jim's sour vs bitter experiment during a presentation he gave on espresso at CoffeeCon.