21 CFR §169.178

1. (a)Concentrated vanilla flavoring conforms to the definition and standard of identity and is subject to any requirement for label statement of ingredients prescribed for vanilla flavoring by § 169.177, except that it is concentrated to remove part of the solvent, and each gallon contains two or more units of vanilla constituent as defined in § 169.3(c).
2. (b)The specified name of the food is “Concentrated vanilla flavoring __-fold” or “__-fold concentrated vanilla flavoring”, the blank being filled in with the whole number (disregarding fractions) expressing the number of units of vanilla constituent per gallon of the article. (For example, “Concentrated vanilla flavoring 3-fold”.)