I’ve only made port twice, both from grapes, 5 gallon carboys, arresting fermentation around 5 brix by adding brandy to where the abv is >20%. This year I have this odd ball 2.5 gallon mini carboy that had the leftovers of what I made this year; Petite Sirah, Petit Verdot and a little Cab Franc. It is a big, dark wine that I added an oak spiral to. The plan is to add brandy to 20% abv and then do taste trials for backsweetening. Should I use white sugar, brown sugar? Any recommendations on how to do the trial?