Definition of tea as a beverage from Camellia sinensis, with caffeine, flavour, tannin and preparation effects. Tea is defined as a beverage prepared by steeping the top leaves and buds of Camellia sinensis in freshly boiled water; its stimulant effect is due to caffeine, flavour from volatile oils, and astringency and colour from tannins. Nutritional notes include low calories when unadulterated and presence of B-complex vitamins. Sensory development increases with steeping time, which is practically relevant for achieving desired flavour and moderate tannin levels.