It turns out that the Food and Drug Administration tightly regulates “eggnog and eggnog flavored milk products” for human consumption. Since 1966, the FDA has prescribed a standard recipe: Products sold as such must contain at least 6% butterfat by weight and at least 1% egg yolk solids. Eggnog flavored milk, on the other hand, may include as little as 3.25% butterfat.
And oh yes, according to the FDA’s CPG Sec. 527.350, “The addition of yellow color may serve to adulterate the products under 403(b) of the Act since the use of such color would make the article appear to contain more egg yolk than it actually contains.”
View entire WSJ editorial on FDA’s regulations.