Mastiha is the resin of the Mastic tree, a dark green shrub which grows wildly on the island of Chios in the northern Aegean. It is often called Mastic Tears, due to the teardrop shape of the ivory resin droplets. Mastiha was probably the first chewing gum in the world and is the root of the word ‘masticate’. It is commonly used in making tsoureki and many other breads, biscuits and pastries, as well as in Greek ice cream and of course it adds a delicious chewiness to any recipe. It is a protected designation of origin food as, while Mastic bushes grow all over the Mediterranean, they only produce resin on the island of Chios and in Çeşme in Turkey. It tastes slightly bitter at first, then turns to a woody vanilla.