Sisi (stylized as SiSi; originally si si) is the brand name of a wide range of fruit-flavoured beverages produced by Dutch beverage manufacturing company Vrumona under a joint venture with Heineken International since 1951. The manufacturing plant is located at Bunnik, The Netherlands. In 1936, George Becht launched a grapefruit-flavoured drink called Ja-Ja. One year later, an apple-flavoured drink was launched under the si si name. After George Becht died in 1949, his son Cornelius took over and adopted the "si si" name to the similar products of the company Vrumona.