After my initial fowl up with sodium meta I found some more ripe frost grapes and started again. around 5 lbs. of grapes. added 1 1/2 campden tablets , waited 24 hours then added yeast 13% variety with 4 cups of sugar. fermentation seemed to go fast by 4 days, wine looked flat(no bubbles. I added 1/8 tsp tannin. hydrometer read wine alcohol content. thought I'd taste a bit. It was pretty bitter so I ADDED ANOTHER CUP OF SUGAR. WAS THIS A MISTAKE? ALSO, I hope it tastes better after a while because it tasted like a bad chianti.