Abstract: An apparatus for supplying hot water to at least one brewing unit (1) operating with pre-packaged pods or capsules (23) containing one or more doses of ground coffee for the preparation of coffee-based beverages, the brewing unit being provided with a brewing chamber (22) and a discharge duct (36) from the brewing chamber for the supply of the prepared beverage, the apparatus comprising a water heat exchanger (4) with a first opening (5) for the introduction of cold water, a second opening (6) for the supply of heated water, a third opening (7) in the vicinity of the first opening (5), and a cold water supply pump (8) connected between a source (9) of cold water and the first opening (5) of the heat exchanger.