The medium batch was on the mild side not too sweet or vinegary. We used 1/3 cup grapefruit juice, 1/2 Tbsp sugar and made 9 bottles.
The large batch was very strong, vinegary. We used it to make plain batch 14 bottles with 1 tsp of sugar.
We pulled the grapefruit at 5 days and it was fine. A little pop and and a nice amount of fizz.