Milk and dark chocolate are categorized by the percentage of cacao in the chocolate – basically, the amount of cocoa solids and cocoa butter from the cacao bean. The higher the percentage of cacao, the more “chocolatey,” and less sweet, the chocolate. White chocolate contains only cocoa butter. For treats like chocolate chip cookies, try chocolates with different percentages of cacao to see what you like best. You may find you like one kind of chocolate in some desserts, like milk chocolate (lower percentage cacao) for peanut butter mousse, but prefer another kind in other desserts, like dark chocolate (higher percentage cacao) for peppermint-flavored truffles.