An 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... 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,... with the bottom machined off so the bottom of the filter basket is exposed. Bottomless portafilters allow you to view distribution problems and channelingChanneling refers to the formation of small water jets during espresso brewing due to poorly distributed grounds. When high-pressure water is forced toward the espresso puck, the water...: if the flow is uneven across the bottom of the filter basket, the distribution of grounds in the basket is uneven.
