I was reminded of this curiosity just moments ago when I got a craving for coffee and couldn't find any normal coffee beans/grounds (owing to the fact that I don't normally drink coffee at home anymore).
I unwittingly purchased this so-called espresso coffee at a supermarket in the heart of the Italian district here, and most of the writing on it is Italian; I didn't even realize my mistake until after I had used it three or four times to brew normal coffee and saw, in very tiny letters, the words "espresso coffee" written on one of the sides.
So I shelved that coffee until today; even though it seemed fine, I figured I might have been using it inappropriately. After my act of desperation today I decided to look this up. According to Wikipedia:
Espresso is not a specific bean or roast level; it is a coffee brewing method. Any bean or roasting level can be used to produce authentic espresso and different beans have unique flavor profiles lending themselves to different roasting levels and styles.
This is what I had always believed. The answer to What factors lead to rich crema on espresso? does hint at a possible difference, though: It says that darker roasts are better for producing crema. However, the coffee I have does not seem to be particularly dark a roast; it's dark, but I've had "normal" coffee that was darker.
Needless to say, I'm a little confused, and the internet is helping me a whole lot. Maybe it's because the caffeine hasn't kicked in yet.
Is there an appreciable difference between coffee beans or coffee grounds labeled as "espresso coffee" and plain, ordinary coffee? If so, what is it?
Perhaps more importantly, is espresso coffee suitable for use in a normal coffee maker or press?