The effect of pH, temperature, and pasteurization time on the total anthocyanin and phenol contents, and antioxidant capacity in a macha macha beverage (Vaccinium floribundum Kunth) was evaluated. pH (3 and 4), temperature (80 and 85 ℃), and time (20 and 40 min) were studied using a complete 23 factorial design. All three variables have shown a significant effect (p < 0.05) on the content of anthocyanins and total phenols, while only time and temperature influenced the antioxidant capacity. It was found that: the anthocyanin content increases with higher pH, while it decreases with time and temperature; the total phenol content decreases with temperature, while it increases with pH and time; and the antioxidant capacity increases with temperature while it decreases with pasteurization time. A pH of 4.0, a temperature of 85 ℃, and a time of 20 min allow greater retention of anthocyanins, phenols (9.7642 mg of gallic acid equivalent/mL), and antioxidant capacity (2.5968 μmol Trolox/mL) in a macha macha beverage. This beverage may have nutraceutical properties and should be optimized with further research.