Why espresso is not a type of bean
Espresso is made by forcing nearly boiling water through finely ground coffee at high pressure. Nothing in that definition names a bean. The National Coffee Association adds that coffee "specifically roasted for espresso will best bring out its characteristics", so roasters do make espresso blends, but those are roast and blend decisions, not a different plant. Wikipedia goes further: "Any bean or roasting level can be used to produce authentic espresso", and it calls the idea that espresso requires dark beans a "widespread myth".
So espresso beans vs coffee beans is really a question about roast and grind. The bag changes; the plant does not.
Where the real difference is: the grind
What changes between espresso and other brews is the particle size. The National Coffee Association's brewing pages give the grind for each method:
| Method | Grind | Why it matters |
|---|---|---|
| Espresso | Fine (like table salt) | Short contact with pressure needs a fine grind |
| Drip | Medium (like kosher salt) | About 5 minutes of contact |
| French press | Coarse (like rock salt) | About 4 minutes of steeping |
Grinding espresso that fine needs a grinder with small, precise steps. See the grind size chart by brew method, and burr vs blade grinders if yours is not up to it.
What to buy for an espresso machine
- Fresh whole beans. Whatever the bag says, grind them just before brewing. Storing beans helps.
- A roast you enjoy. Roast preference varies; Wikipedia notes darker roasts are generally preferred in southern Italy and slightly lighter roasts farther north.
- Not necessarily an "espresso" label. It signals the roaster's intent for espresso, not a rule. Try a few and taste.
Can you use regular coffee beans for espresso?
Yes. Grind them fine enough for your machine and adjust until the shot runs in the usual window. The National Coffee Association gives 20 to 30 seconds and a 1:2 ratio as a starting point, which the espresso ratio calculator works out for your dose. If the shot tastes sour or bitter, that is a dialling problem to fix, not proof the bean is wrong: see how to dial in espresso at home.