I need some insight into what I think is an issue I am having with my first attempt at a non-kit wine. I am making black raspberry wine from berries harvested locally in central Ohio. They were harvested last summer and frozen. I thawed the berries in January 05 and ran them through a strainer - one of those hand crank jobs from Back-to-Basics. I added whelches white grape juice to the raspberry juice to increase the volume and add balance. Fermentation when well and have racked a couple of times. I have been bulk aging since February. Now for the problem. The clearity/color is excelent, bouquet is wonderful, and the taste starts well. The problem is that it finishes with a very sharp bitting biterness. Could this be flavor imparted from the seeds? Will it go away on its own? My intent was to take 1/2 of the 5 gallon batch and sweeten it and leave the other 1/2 dry. I am wanting to bottle soon but don't know if I should if there is something I should do about this bitterness.
Suggestions?