We pulled the large batch after 7 days and it was weak and sweet. We juiced 8 grapefruits and used 1/3 cup grapefruit. 8 bottles had 1/3 cup grapefruit juice and 1 Tablespoon of sugar. 7 bottles had 1/3 cup grapefruit juice and 1/2 Tablespoon of sugar.
The medium batch was also sweet, a little stronger than the large batch but still weak. We did 1 teaspoon of sugar and made 9 bottles.
Pulled the grapefruit at 2 days and it was perfect. The 1 Tbspn sugar was popular but I thought it was too sweet and I thought the 1/2 tbspn was just right. One of the old bottles (1/2 Tbspn) did not fizz/ferment and may have been not been capped properly.