Crush blackberries in a large kettle. Add water and bring to a boil. Reduce heat to medium and cook for 10 minutes. Strain through a jelly bag, reserving juice and discarding pulp. Add water to juice if necessary to equal 2 quarts; pour into a large kettle. Slowly stir in sugar until dissolved. Place spices in a cheesecloth bag; add to juice. Simmer, uncovered, for 30 minutes. Bring to a boil; remove the spice bag and discard. Pour hot into hot jars, leaving 1/4' headspace. Adjust caps. Process for 15 minutes in a boiling-water bath. To serve, mix about 1/3 concentrate with 2/3 soda. Yield: about 4 pints concentrate