A Bottomless (Naked) Portafilter allows the barista to view any problems that may be present during the espresso extraction. Ideally, there will be a uniform extraction through the entire coffee cake. The use of a naked portafilter will immediately show if there are any spots that are over or under extracting. The barista can then modify their technique or possibly their tamper to achieve a better extraction.
Please specify your Brand and Model of espresso machine so that we can send you the appropriate naked portafilter. (We have naked portafilters for all popular brands including all E61 group head machines - Vibiemme, Rocket Giotto, Diadema, Bezzera Domus Galatea, Expobar and non E61 group head machines such as the Rancilio Silvia and Bezzera BZ07).