The meat mutton comes from a sheep that is at least how old?

'Mutton' is the meat from a sheep over two years old. It is less tender and darker in colour than younger sheep. The meat of younger sheep is generally called 'lamb', but some countries refer to all sheep meats as 'lamb'. Mutton can taste more flavourful than lamb because it contains a higher concentration of fatty acids.

Mutton was widely consumed in the United States during the early 1900s but has declined since the end of the Second World War. In the 21st century, the United States permit all sheep products to be marketed as 'lamb', regardless of the animal's age.

In South Asia, meat from goats is also called mutton. 'Kosha mangsho', or mutton-curry, is nearly always made from goat's meat. This is because the population of sheep in the area has reduced significantly over the past few decades. Sheep are usually kept for their wool instead.

According to the Organisation for Economic Co-operation and Development (OECD), Greece is one of the highest lamb and mutton consumers in the world, followed by Serbia, Kazakstan and Australia.