Greg, the color will change once the fermentation stops and the yeast start a massive die-off. Right now you are seeing the color of the wine with billions of microscopic bubbles of CO2 suspended in it, so it will be lighter in color (creamier is what one friend calls it) because the bubbles refract light incident upon them. Forget the physics lesson and trust me on this. When the wine "falls clear," the darker color will start at the top and work its way down. It will change from an opaque "bright red" to a transparent "dark reddish-purple."
I really don't know if this is true or not, but a friend told me that whatever is to be extracted from skins, pulp and seeds -- whether we're talking about blackberries, grapes or apples -- will have been extracted in the first three days of vigorous fermentation. If true, then it is already too late to prevent additional tannins or other phenolics from being integrated into the wine from the seeds. If not true, you still have time to presss....
I watched a commercial winery prepare blackberries for wine. They had been frozen in 5- and 6-gallon buckets about three weeks and were moved into the 65-degree winery. After three days, they were poured into a mixing vat and given a dose of liquid pectic enzyme. Every hour they were mixed with an inserted impeller for about 2-3 minutes. After six hours, there was lots of free-run juice and they were pumped into a bladder press and the juice extracted and pumped into a tank. About six pressings were required to process the entire batch. The juice was analyzed and chaptalized, ameliorated with just enough water to drop the acid to 6.0, and a gallon was drawn off and into it the yeast nutrients were dissolved and then added to the batch. A starter solution for the yeast had been activated that morning and was added to the batch. Only the juice was fermented. They avoided seed contact altogether.
I have never made it that way even though I have now made several batches of 100% blackberry juice wine, only diluted to correct acidity. I make it similar to what you are doing, but wait for the cap to collapse before pressing.
Plant blackberry plants only where you have no intention of ever using the land for other purposes. Every wild blackberry ot dewberry I have planted took over its environs and were a real nighmare to eradicate later. I now grow only thornless Navajo blackberries. They are big, delicious, upright, and -- did I mention? -- thornless. And I don't care if they take over the area I've planted them in.
Jack Keller, The Winemaking Home Page
formatting link