U.S. patent application Ser.  No.  10/328,774, relates to a capsule cage or cartridge, capable of being mounted in a coffee machine, comprising a first part with a channel for the supply of water and a second part forming a housing for the capsule for extraction, in which a perforation system independent of the water-supply channel is provided directly at the exit from the said channel.  The cartridge with the means for retention of solid substance, as mentioned above, is insufficient to guarantee complete cleanliness when changing cartridges.