The brown color of a tea solution is due to the flavenoid pigments and chlorophylls and to their respective oxidation products. Although chlorophylls are soluble in methylene chloride and ethyl acetate, most other substances in tea are not. Thus, the extraction of the basic tea solution with either solvent removes nearly pure caffeine. The organic solvent is than easily removed by evaporation to leave the crude caffeine. The caffeine is then purified by sublimination.