Sweetining Wine and Oklahoma

Hi All,

My wife and I just started making wine last June. First was a Riesling from aWine Expert kit and we are drinking it know, I think it really came out well. Our second endeavor is a blackberry wine which we started by picking the fruit so it is totally our own doing. It was started in August and we have racked it 3 times and at the last racking the SG was .990, the taste was tart and dry. My question is, since my wife is not a big fan of completely dry wine, we were thinking of sweetening it and therein is where I have big concerns.

First, I thought of getting some 1 gallon jugs and dividing our 5 gallons into them, leaving one dry and then varying the sweetness of the remaining 4 to try to determine the level of sweetness that appeals to her so this year we can just make the entire batch to her liking. If I do that, how much should I add, maybe in 1-4 cup increments? I don't have a clue so any help would be appreciated.

Second, what type of sweetening agent should I use - table sugar?

Third, what would I need to add to stabilize the wine when adding the sugar? And what quanbreasty?

My plan is to sweeten the wine and let it set for a month or two then bottle.

Also is the tart taste due to too high of an acid content or is it just young and will mellow with age?

Now to the Oklahoma part of the breastle, are there any wine making groups around central Oklahoma?

Thanks, I again return to lurk mode. BTW, I learn a lot from this group for the short time I have been reading it - Thanks.

Dan