There are a number of techniques in brewing coffee; concentrate brewing, Turkish or Greek, Vacuum brewing, percolating, or the french press (also called press pot or plunger coffee).

Like all coffee drinks, caffeine levels very greatly - due to variations in coffee blend and brewing technique.

The value of caffeine in brewed coffee is an average, with values generally between 80 and 135 milligrams per cup. Brewed coffee means that the water is in contact with the grinds for a long time - leading to a higher caffeine concentration (and sometimes an overextracted taste!).

Generally, coffee blends used in brewed coffee tend to have more of the robusta bean than the arabica bean. Robusta is a more potent (and cheaper) coffee bean.