Tereré is a refreshing beverage made with yerba mate, water and ice. It is popular in Paraguay, Uruguay and Argentina.
Yerba mate (Ilex paraguariensis) is a species of holly native to South America. It is brewed like tea and has high levels of caffeine. Mateine, a psychoactive alkaloid found in yerba mate, is structurally similar to caffeine but produces different effects. Yerba mate also contains antioxidants, vitamins and minerals.
Water for tereré is traditionally sourced from a guampa (gourd), which imparts subtle flavor to the drink. The guampa is filled with water and placed in the sun to heat up. Once it reaches the desired temperature, the water is poured into a mates cup (a special cup for drinking yerba mate) along with yerba mate leaves and ice cubes.
Tereré can be enjoyed plain or flavored with fruit juice or herbs. Popular fruit juice flavors include: lemon, orange, grapefruit, strawberries and mandarin oranges. Other popular flavors include: mint, basil, anisette and Fernet-Branca (an Italian liqueur).