Annatto Seed is used in Latin American and Caribbean cuisine to give food a rich savory flavor and striking color. The tiny, hard seeds are often infused into oil to make them easier to use, resulting in a deep red liquid that can be kept on hand to quickly add to meat, rice, or other recipes.
The vibrant hues imparted by annatto are surprisingly common. The yellow tint of Latin rice, for example, comes from annatto oil. Annatto extracts are also responsible for making butter yellow, and for the orange color of cheddar cheese.