Bittersweet chocolate is chocolate liquor (or unsweetened chocolate) to which some sugar (typically a third), more cocoa butter, vanilla and sometimes lecithin has been added. It has less sugar and more liquor than semisweet chocolate, but the two are interchangeable in baking. Bittersweet and semisweet chocolates are sometimes referred to as ‘couverture’ (chocolate that contains at least 32 percent cocoa butter); many brands now print on the package the percentage of cocoa (as chocolate liquor and added cocoa butter) contained. The higher the percentage of cocoa, the less sweet the chocolate is. The American FDA classifies chocolate that contains at least 35% cacao (either cacao solids or butter from the cacao beans) as either “bittersweet” or “semisweet”.