The results obtained give a clear confirmation that the yogurt bacteria did not affect significantly (P < 0.05) the composition of the phenolic compounds of green and black teas. Before the beginning of production and storage trials, preliminary studies were conducted to see the effect of tea addition to milk on acidity during fermentation. The acidity of milks dropped as expected over the 6 h period of incubation and no significant(P < 0.05) differences (Fig. 5) in acidity were observed among the treatments, indicating that tea neither supported nor impeded lactic acid production by S. thermophilus and L. bulgaricus at this stage.