I’ve heard that looking at the coffee puck after making an espresso can tell you a lot about the technique and how the extraction went. This morning I was taking the bowl that I put the coffee pucks from making espresso out to the compost pile, and for some reason decided to take a look at one of them. That’s when I realized that although the pucks looked pretty good to me, I had no idea as to what I should be looking for.
Here’s a picture of one. I lightened the picture to bring out the detail. The actual puck is darker brown than what’s seen here.
What I can see is that there aren’t any holes, and that the surface is pretty uniform in terms of color and texture. It looks like the edge of the puck is darker in the lower left quadrant, but that’s bad lighting.
Is this the goal? Am I missing anything?