Not really chocolate at all, white chocolate contains no chocolate liquor, which means it has little, if any, chocolate flavor. The FDA has established a standard of identity for white chocolate as a product that contains cocoa butter, milk solids, nutritive carbohydrate sweeteners and other suitable ingredients, such as lecithin and vanilla. Melt white chocolate very slowly over low heat to keep it from scorching and clumping.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.