This mug is only for hot chocolate. For coffee and tea see here.
Theobromine, also known as xantheose, is a bitter alkaloid of the cacao plant, found in chocolate, as well as in a number of other foods, including the leaves of the tea plant, and the kola or cola nut. It is in the methylxanthine class of chemical compounds, which also includes the similar compounds theophylline and caffeine. Theobromine is derived from Theobroma, the name of the genus of the cacao tree, (which itself is made up of the Greek roots theo (“God”) and brosi (“food”), meaning “food of the gods”) with the suffix -ine given to alkaloids and other basic nitrogen-containing compounds. (from Wikipedia)