A process of producing beverage includes washing and drying cactus fruit and pitaya juicing the cactus fruit to obtain juice of the cactus fruit and juicing the pitaya to obtain juice of the pitaya respectively filtering the juice of the cactus fruit and the juice of the pitaya respectively mixing the filtered juice of the cactus fruit and the filtered juice of the pitaya with water to obtain a solution pouring yeast and gram-positive bacteria in the solution wherein the yeast is saccharomyces boulardii and the gram-positive bacteria includes lactobacillus acidophilus and bifidobacterium longum and fermenting the solution until beverage is produced wherein fermentation temperature is between 26° C. and 35° C. and fermentation time lasts for 3 to 10 days.
