A classic espressoA small coffee beverage, about 20 ml, prepared on an espresso machine where pressurized hot water extracted through compressed coffee.: In its most stripped-down, basic form, this is... group-head design, originally invented by Faema and used on a varietyA botanical variety is a rank in the taxonomic hierarchy below the rank of species and subspecies and above the rank of form (form / variety / subspecies... of machines. The E61 is easily identified by its pre-infusionAn espresso machine is said to use pre-infusion if it applies a moderate amount of pressure to the coffee before applying full brew pressure. Pre-infusion is often said... chamber located just behind the portafilterThe part of an espresso machine which holds the filter basket, into which coffee grounds are placed.: The part of an espresso machine which holds the filter basket,... and by its small external lever used for activating the brew cycle.