I'm using a Carimali grinder and this week have been pulling great shots of Counter Culture Twin City Express (roasted 1/31) with my ECM Giotto. The grinder is set at 3.4 (generally I grind between 3 and 3.5). On Friday I received a sample of an espresso blend and this morning I figured I'd give it a try so I cleaned the grinder, and poured in some of the new blend. At 3.4 my cup was full in about 4 seconds so I dropped it down to 3.1. Maybe 10 seconds. So, for the first time ever, I dialed down to 2.8 (didn't sound good) and gave it a little extra with the tamper. Close, but still too fast. That shot I tasted, but I didn't like it so I cleaned the grinder, put it back on 3.4 and went back to the Twin City Express. Gorgeous, thick, creamy 25-second shots. So is the other coffee stale? A harder variety? Dehydrated? This may be elementary, but I couldn't find the answer. Thanks for your thoughts.

How long ago was it roasted? It could be stale and running fast, or it could be ultra fresh and needs more degassing time. Stale beans have almost no crema; too fresh and it will be all crema, but will go flat in seconds.

The degree of roast along with the type of beans used will also make a difference, along with humidity. I have a couple of blends that will shift quite a bit on the grind just because of the beans used.

Humidity is also a factor...