I started with a raspberry puree from MS to make the slurry. I made a 1 gallon batch of that. I used ReaLemon from the bottle and started the batch in a wine fermenter, only used for wine. I use one step sanitizer and clean like crazy. All the water I used had been boiler prior to use. I strained out solids at the first racking into a carboy. The batched fermented well, ending at 10% ABV, and cleared crystal clear.
What I'm wandering is if the puree and 1 gallon slurry was enough to give the batch more of a traditional wine composition, thus resulting in it needing to age to get past the bitterness.
I have taken 1 gallon and back sweetened with 2/3 cup of sugar and will let that sit for awhile to see what happens. The resulting wine is about 10% ABV so it shouldnt hurt to sit arround for awhile.