Anything you buy from George(This Site is 100% guaranteed and thats what separates George from the rest!!!!!!!!!! As for upping the abv it would really not hide much flavor but will take a little longer to ferment and to age. The higher the abv in the wine the longer it will take to mellow out for the flavors to come through. It is the reverse of oaking a wine as it takes time for the oak to blend in.