Samuel Kwok’s recipe, good for 33 oz: pour 23 oz of apple juice into a saucepan. Add 3 oz of ground ginger and bring to a boil while stirring. Cook for an hour on a medium flame. Pour into a separate container and mix with 50 oz of sugar. Then mix the resulting 500 ml of syrup, 400 ml of Greek yogurt, and buttermilk. Carefully mix and filter into a separate container. Cool and store in the refrigerator.