What does 2,000-year-old butter taste like?

A lump of butter believed to be around 2,000 years old has been found in an Irish bog. It's about the size of a small suitcase. But what does ancient butter taste like? Kevin Thornton, a Michelin-star chef in Dublin, describes the sensation.

(Photo: Kevin Thornton (L) holding bog butter. Credit: Bizarre Foods)