Technical Abstract: To develop a better understanding of compositional changes occurring during the production of commercial teas, we determined by high-performance liquid chromatography (HPLC) changes in ingredient levels during each of several manufacturing steps used to produce Kamairi-cha, a premium green tea. We used pan-frying instead of the usual blanching technique to inactivate the enzymes responsible for producing traditional black tea. The resulting tea lacks the characteristic bitterness of green tea, producing a green tea that is described as sweet-tasting. The processing steps used to produce this pan-fried tea were as follows: first roasting, first rolling, second roasting, second rolling, first firing, and second firing. The results show that during production at temperatures up to 300 °C, raw leaves lost (in %) 97.3 water, 94.0 two chlorophylls, 14.3 seven catechins, and 2.75 caffeine. A separate analysis showed that the final product contained 21.67 mg/g dry wt of the biologically active amino acid theanine. The results of this first report on changes in individual catechins and other tea ingredients in tea leaves during pan-frying make it possible to select production conditions that maximize levels of beneficial tea ingredients. The possible significance of the results for the human diet is discussed.