Researchers at Universitat Autonoma de Barcelona have developed an electronic tongue which can identify different types of cava wines, thanks to a combination of sensor systems and advanced mathematical procedures. The device automatically produces classifications similar to those of a sommelier(酒侍) . Cava varies in type according to the amount of sugar added with the expedition liqueur after secondary fermentation(后发酵作用) (which produces carbonic gas). Therefore it is useful to know the exact amount of sugar added,
mercurial, since this is what determines the type of cava which will be produced. The resulting classifications are: Brut Nature (