A beverage dispenser has a supply opening that supplies an aqueous liquid from a source; a recooling heat exchanger having a heat receiving portion, a recooling inlet and a recooling outlet; a reverse osmosis filter having an inlet for aqueous liquid, a permeate outlet and a concentrate outlet; and a cooling device having a cooling portion extracting heat energy from the permeate and a heat dissipation portion dissipating energy to the heat receiving portion of the recooling heat exchanger. The heat dissipation portion of the cooling device is thermally coupled with the heat receiving portion of the recooling heat exchanger. The cooling portion of the cooling device is thermally coupled with the permeate exiting the permeate outlet of the reverse osmosis filter, wherein the permeate enters the cooling portion by a cooling portion permeate inlet and exits the cooling portion by a cooling portion permeate outlet.