The invention relates to an apparatus for preparing a beverage, for instance baby milk, from an instant product, such as formula, and water, which has been sterilized and cooled down to a temperature suitable for consumption. The apparatus comprises a water supply system for supplying water, a heating system for sterilizing the water, a cooling system for cooling down the sterilized water and a bypass, which allows sterilized water from the heating system to bypass the cooling system. Thanks to such configuration, hot water from the bypass can be added to cool water from the cooling system so as to bring the temperature of the cool water to a desired consumption temperature.