Being in the espresso industry since 2004, we have come to learn a thing or two about creating an excellent espresso. We used to make the rookie mistakes and thought that a finer grind would always produce a better espresso...not the case! Let your coffee grounds tell you what you need to do...or change. The coffee grounds never lie. Anyhow, we don't know what your coffee grounds are telling you but below are some pictures of what your coffee grounds should look like. We'll also go into a little bit of detail about what you can change.
After you pull a shot of espresso, the top of the grounds should be damp but not have a pool of water (it should NOT look like muddy water). If you take your finger and press into the grounds, you should be able to make an indent in it only (think of the sand at the edge of the beach, if you press down on it with your fingers, it has a damp, hard, and spongy type of feeling).
Another quality your grounds should have...when you knock it out, it should stay in one piece and you should be able to pick it up and analyze it. If you aren't able to do this, try a more coarse ground but a larger dose. Yes, I said it...more coarse. Finer isn't always better.
It is mandatory that you use a Burr grinder. If you have a blade grinder, put it in it's original box and give it to your grandfather so he can use it to grind up black pepper, it'll make his day, I'm sure. Spend a little bit of money and get a Burr grinder for goodness sakes! Espresso is not a joke, and if you're to cheap to get a Burr grinder, than maybe you should give up trying to make your own espresso.
If you break the used coffee grounds in half, you should see that the entire portion has been wet. This means that the entire dose of espresso has had water pass through it, ensuring a maximum flavour in the cup.
