Use fresh, juicy berries such as blackberries, boysenberries, loganberries and raspberries.
Place berries in a large pot. Crush; and heat until berries are soft and render their juice. Strain through jelly bag or a colander lined with four layers of cheesecloth into a large bowl. For a greater yield of juice, twist ends of bag or cheesecloth until most of the juice is extracted. See Note. Measure and return juice to large pot; add 1 to 2 cups sugar to each gallon of juice (or to taste). Reheat to dissolve sugar.
Pour quickly into clean, hot jars, leaving 1/2-inch headspace; seal. Process pints or quarts in boiling water bath for 15 minutes.
NOTE: If you want a clearer juice, before adding sugar let juice stand for 24 hours in refrigerator. Carefully ladle juice into pot without disturbing the sediment; add sugar, then proceed with recipe.