A new method for Espresso Coffee brewing: Caffè Firenze

Espresso coffee is the most popular choice for Italian coffee consumers. It has been estimated that every day, in the world, over of 50 million of Espresso cups are taken. As a consequence of this success, a large number of devices to make Espresso have been developed. In this scenario, a new device has been recently developed and patented (Eu. Patent 06 023 798.9; US 2010/0034942 A1). This brew method, named “Caffè Firenzeâ€, uses a sealed extraction chamber, where water and gas provides pressure higher than the other extraction methods. Three main parts compose the apparatus: the gas source, the extraction chamber and the heat exchanger. The gas source provides the pressured gas required to raise the pressure of the system. The extraction chamber is made with chrome-brass and accessorized with two heating glow plugs. Many are the factors affecting Espresso quality: it is known that, coffee type, roasting conditions and degree, grinding and storage strongly affect the obtained brew. Also, several studies have been carried out on the effect of the setting parameters on quality, for example water pressure, water temperature, and brew time. Among the characteristics that determine Espresso quality, the main attribute for the visual analysis is, without doubts, the foam, also called “cremaâ€. Indeed, height, aspect, and persistency of foam are features much appreciates by consumers. Two distinguish Espresso foam parameters are the persistency and foam index. Equipping a commercial bar machine with the new designed extraction chamber makes feasible the comparison between the traditional way to brew Espresso and the new device. The comparison was made holding the previous mentioned conditions, and differences were evaluated in terms of physical parameters and aromatic profiles. Caffè Firenze shows pronounced differences compared with traditional Espresso in term of foam-related parameters. Also, the new extraction device produces coffees with higher values of body-related parameters, such density and viscosity. The two kinds of Espressos are perceived different at visual analysis and taste by a panel test.