Coffee and Caffeine FAQ

First, a disclaimer: I am an espresso enthusiast, and make it on a daily basis from a very high-quality home espresso machine. The following is conventional wisdom among espresso enthusiasts. More importantly, it is what I have found from making a few good cups and many indifferent ones -- thankfully the bad ones are few and far between.

Crema from espresso should NOT be a uniform, light color. Whenever I am served (or make) espresso that has this appearance of crema I know to expect that the cup will taste sour and/or watery. If you observe the crema coming out of the portafilter spouts you will notice that it starts out a rich brown and becomes a blond color towards the end. The taste of the coffee coming out is better for the first drops than the last -- the correlation is no accident. In fact, a thin stream (stated as the time the shot should be ended) is almost ALWAYS blond.

See http://www.home-barista.com/naked-extraction.html for signs of a good cup.