Blackberry wine

[stallion_371110]

I made some Muscadine wine with much success last year. So, I thought I would try Blackberry. I learnt on the Muscadine 22 cups sugar makes it taste sour and 8 cups makes it very sweet.
I added 6-8 cups Blackberries
8 cups sugar
3 packs of yeast
3 gal. water
I wanted the Blackberry wine to be sweet
1 month later which is today Aug. 22nd
I put it into its glass containers today and sipped it and it tastes sour as the Muscadine with 22 cups sugar in it. I left the Blackberry outside and didn't put it in the dark as I did the Muscadine. Is that where I went wrong?
Is there a way I can sweeten it up? Can I retry ferment stage? I'll try anything except standing on my head.
Thanks to anyone who replies.

 

[estricklin]

Sour like vinegar? Lacto infection?

Its strange that less sugar could someone make it sweeter? What type of yeast did you pitch? Did you take a starting gravity reading?