The Food and Drug Administration (FDA) sets standards of identity for many types of chocolate, regulating what ingredients different versions of chocolate must contain. The most crucial ingredient for standard of identity is chocolate liquor, which is a liquid chocolate made from grinding the center of the cocoa bean. Chocolate liquor contains no fat and is sold in a solid form as baking chocolate.

Milk chocolate, which is the most commonly sold chocolate in the United States, must contain at least 10 percent chocolate liquor and at least 12 percent milk solids. Cocoa butter and milk solids are the only fat allowed in milk chocolate.

Semisweet chocolate must contain at least 35 percent cocoa butter to meet the FDA standard of identity. Sweet chocolate must have at least 15 percent chocolate liquor, and typically contains more sweeteners than does semisweet chocolate.

The FDA established a standard of identity for white chocolate in 2002. White chocolate must contain 14 percent milk solids, 20 percent cocoa butter and less that 55 percent sugar. It may not contain any chocolate liquor.

The FDA also sets standards of identity for chocolate liquor, cocoa, skim milk and buttermilk chocolate, and coatings that combine chocolate with vegetable fats. It does not set any standard of identity for dark chocolate.