Why butter is yellow while milk is white: The science behind it

 Milk appears white because microscopic particles scatter all visible light wavelengths equally. Butter’s yellow hue comes from beta-carotene stored in milk fat from cattle’s diet. The shade of yellow butter varies based on the freshness of grass consumed by cows. Some butter appears white when cattle convert beta-carotene into vitamin A. Manufacturers sometimes add annatto for a consistent golden butter appearance year-round. Milk appears white because microscopic particles scatter all visible light wavelengths equally. Butter’s yellow hue comes from beta-carotene stored in milk fat from cattle’s diet. The shade of yellow butter varies based on the freshness of grass consumed by cows. Some butter appears white when cattle convert beta-carotene into vitamin A. Manufacturers sometimes add annatto for a consistent golden butter appearance year-round.