Chocolate liquor is blended with the cocoa butter in varying quantities to make different types of chocolate or couvertures. The basic blends of ingredients for the various types of chocolate (in order of highest quantity of cocoa liquor first), are:
Fountain chocolate is made with high levels of cocoa butter, allowing it to flow gently over a chocolate fountain to serve as dessert fondue.
Dark chocolate: sugar, cocoa butter, cocoa liquor, and (sometimes) vanilla
Milk chocolate: sugar, cocoa butter, cocoa liquor, milk or milk powder, and vanilla
White chocolate: sugar, cocoa butter, milk or milk powder, and vanilla
Usually, an emulsifying agent, such as soy lecithin, is added, though a few manufacturers prefer to exclude this ingredient for purity reasons and to remain GMO-free, sometimes at the cost of a perfectly smooth texture. Some manufacturers are now using PGPR, an artificial emulsifier derived from castor oil that allows them to reduce the amount of cocoa butter while maintaining the same mouthfeel.
The texture is also heavily influenced by processing, specifically conching (see below). The more expensive chocolate tends to be processed longer and thus have a smoother texture and mouthfeel, regardless of whether emulsifying agents are added.
Different manufacturers develop their own "signature" blends based on the above formulas, but varying proportions of the different constituents are used. The finest, plain dark chocolate couvertures contain at least 70% cocoa (both solids and butter), whereas milk chocolate usually contains up to 50%. High-quality white chocolate couvertures contain only about 35% cocoa butter.