Pressurized beverage package having an interior chamber for the production of foam on opening the package

A beverage package comprising a sealed container with a base and a side wall upstanding from the base carrying an openable top;

• the sealed container having a primary chamber containing beverage having gas in solution therewith and forming a primary headspace comprising gas at a pressure greater than atmospheric;
• froth developing means comprising an assembly of a secondary chamber and a tube, the secondary chamber containing gas at a pressure greater than atmospheric and having an outlet port in the primary chamber remote from said side wall, said tube having one open end thereof fitted in sealed communication with said outlet port and extending upwardly from said outlet port within the beverage of the primary chamber to locate a second open end of the tube nearer to the openable top than to said outlet port;
• said froth developing means being arranged so that when said openable top is opened to open the primary headspace to atmosphere, said opening creates a pressure differential which causes pressure from gas in the secondary chamber to eject from said second open end of the tube at least one of gas, beverage and froth and said ejection causes froth resulting from gas liberated from solution in the beverage to develop in the primary headspace, and wherein said tube is pre-curved over its longitudinal extent between said one and second open ends thereof to locate said second open end adjacent to said side wall for said ejection to be effected adjacent to that side wall.