The present invention relates to an apparatus and a method for brewing a beverage. The apparatus is for attaching with an espresso machine which has a boiler for heating water and a group head for discharge of heated water from the espresso machine, the group head having an attachment bracket for attachment in a sealing manner to other devices to which delivery of heated water is desired, the apparatus comprising in combination: a brewing enclosure having a brewing chamber therein, an agitator located within said brewing enclosure, an outlet in fluid communication with said brewing chamber a water outflow restriction device located between a lower end of said outlet and said brewing chamber, said outflow restriction device having a flow rate less than a maximum flow rate of water exiting the boiler of the espresso machine and passing through the group head, such that residence time for the water adjacent the brewable substance is increased; and wherein said water outflow restriction device includes an at least partially manually adjustable valve.