TrlstanC wrote:For me sour and bitter have just become short hand ways of saying over extracted and under extracted. When I'm trying to explain sour and bitter to someone who doesn't drink much espresso (or at least hasn't thought much about the espresso they drink) it's tough for them to determine what's sour and what's bitter, but when I describe it as under extracted then they can taste it.

When I first started trying to make good espresso I couldn't really tell what was over or under extracted, so it was tough to figure out how to fix my shots. Things got easier the first time I pulled apart my grinder to give it a good cleaning (months over due at that point), and I had to get it dialed back in. I got some shots that were 10 second gushers and some that gave a couple drips after a minute before getting back to normalcy, but I took a taste of all the shots (whereas usually I would've just tossed anything that looked that bad). This gave me a much better frame of reference, and it was easier to pick out the same tastes in shots that were just a little off in the future.

The other big thing I learned was what a big impact stale grinds can have on taste. I was always good about sweeping it out as much as I could, but until I got in there and cleaned out the built up gunk hidden in the corners I didn't realize how much funkiness was ending up in the cup. Now I'm religious about thurough cleanings (grinder, machine, baskets, everything) and it's night and day. Getting rid of a little bit of funkiness makes it that much easier to pick out, and enjoy, all the other flavors.