Wikipedia Article About Kefalotyri on Wikipedia Kefalotyri is a rather hard, salty yellow cheese made from sheep and/or goat milk in Greece (cow's milk is not allowed). Depending on the mixture of milk used in the process the color can vary between yellow and white. Being a very hard cheese, Kefalotyri is consumed as is, fried in olive oil or added in foods such as spaghetti, meat, or cooked vegetables. This is a very popular and well-known cheese, establishing its roots in Greece during the Byzantine era. It takes from two to three months to ripen.