The present invention provides an apparatus for cooling and/or gassifying a liquid (12) stored in a container (10) having an outlet (10b). The apparatus comprises an adsorbent (14) for receiving and adsorbing under pressure a quantity of gas and a three position cap (16). In a first position, said cap (16) simply acts to seal the contents within the container whilst in a second position it acts to cause release of adsorbed gas from adsorbent (14) which then passes through the beverage (12) thereby gassifying and/or cooling said beverage. A third position of the cap (16) allows for its removal from container (10) such that the beverage may be dispensed. The container may be provided with a thermochromatic coating to indicate when the liquid is at a predetermined temperature.