You can add additional sugar any time before stabilizing. My goal was 9.5% abv ( a little gutsier than the wine was designed for ) and not too sweet. That's why I added half of the F pack at the beginning (I didn't want to lose the flavor) and a couple of pounds of sugar.
If you want to add sugar now be sure to take a sg reading before and after so you can calculate the increase in abv.
Admiral, I did add the rest of the F-pack after stabilizing. The half F-pack added just the right amount of sweetness, according to my daughter, SWMBO, and her friends.
OK! I started this wine at 1.048. It fermented 3 days to 1.030. I added 2# of corn sugar and 1/2 of the F-Pack which brought it back to 1.044. So, if it ferments to 1.000 what will be the ABV?
