Espresso is made with hot water at between 91 *°C (195 °F) and 96 °C (204 °F) forced, under a pressure of between eight and nine atmospheres (800-900 kPa), through a tightly packed matrix (called a puck) of finely ground coffee. It can be served alone (often after an evening meal), and is the basis for many coffee drinks. It is one of the strongest tasting forms of coffee regularly consumed, with a distinctive flavor and crema, a layer of emulsified oils in the form of a colloidal foam standing over the liquid.
A moka pot , also known as "Italian coffeepot" is a three-chamber design which boils water in the lower section and forces the boiling water through the separated coffee grounds in the middle section. The resultant coffee (almost espresso strength, yet without the crema) is collected in the upper section. It usually sits directly on a heater or stove. Some models feature a glass or plastic top to view the coffee as it is forced up.
Various types of single-serving coffee machines force hot water under pressure through a coffee pod composed of finely ground coffee sandwiched between two layers of filter paper or a propriatary capsule containing ground coffee. Examples include the pod-based Senseo and Home Café systems and the propriatary Tassimo and K-Cup systems.