Blackberries are known to produce a table wine, resembling a red Bordeaux. Blackberrry wine is, also, friendly to barrel aging. Remember to add pectic enzyme powder to every must. Blackberries contain a large quantity of pectin, and if not broken down by the enzyme, the wine can - literally - evolve large, reddish-black blobs, floating in the wine.
Add the next 5 ingredients. Stir.
Adjust the specific gravity with an hydrometer to 1.100 by adding sugar. With an acid testing kit, shoot for about 5.0 g/L by adding acid blend (see the manual of your kit for specifics).
Raise or lower the temperature of the must to keep it a constant 75F.
Prepare the yeast to package directions. Add yeast. Cover the fermenter with a lid or food-grade plastic. Stir the must twice daily. When fermentation kicks in, move the primary to a cooler location (65F) - if possible. Check the specific gravity every day. (A 10 point or more drop per day should be expected.)
When the specific gravity hits 1.020, squeeze the bag to release most of the juice, then siphon the new wine into a clean, 5 gallon glass carboy. Attach an air-lock to a 6 1/2 size white, rubber bung, fit the bung into the neck of the carboy then fill the air-lock half-full of water.
When fermentation entirely ceases, rack (siphon) the wine into a clean carboy. Top off the carboy with cold, tap water, leaving no more than two inches of head-space between the wine level and the bung of the air-lock. Attach an air-lock. Allow the wine to rest for 4 weeks.
Rack the wine into a clean carboy. Add the bentonite finings (prepare as the directions on the package indicate). Top off the carboy with water. When the wine becomes sparklingly clear (about 2 weeks), rack it into a clean carboy. Sulphite the wine with 1/4 Tsp potassium metabisulfite made into a slurry with water. Top off the carboy with water. Attach the air-lock. Bulk age 3 months.
Bottle the wine. Bottle age 6 months. Drink.
Some winemakers insist that bentonite is not suitable for fining red wines. They reserve it for whites. Gelatin has been a time-honored fining agent for red wines. However, gelatin (unlike bentonite) does not form a firm sediment on the floor of the carboy. Be careful when racking the wines fined with gelatin. Bentonite and gelatin, used in combination as fining agents, result in good clearing and compact sediment formation.
KC Finings have been palmed-off as "the perfect fining agent for red wine". However, I have not had success with KC Finings. I suspect that the chemical constituents (Kieselsol and Chitosan) were old, and they made the wines cloudy, which only bentonite could clarify!
Refer to my Apricot wine recipe for a fuller understanding of the winemaking process.
Here is another fine, though somewhat more technical guide by the apostle of home winemaking Stanley F. Anderson: Winemaking.