Juice from fresh or frozen raspberries (black or red), as well as blueberries, cherries, grapes and strawberries are easily made into toppings for use on ice cream and pastries.
Procedure: Select 6-1/2 cups of fresh or frozen raspberries. Wash, cap and stem fresh fruit and crush in a saucepan. Heat to boiling and simmer until soft (5 to 10 minutes). Strain hot berries through a colander and let drain until cool enough to handle. Strain the collected juice through a double layer of cheesecloth or jelly bag. Discard the dry pulp. The yield of the pressed juice should be about 4-1/2 to 5 cups.
Combine the juice with 6-¾ cups of sugar in a large saucepan, bring to boil and simmer 1 minute. To make a syrup with whole fruit pieces, save 1 or 2 cups of the whole fresh or frozen fruit, combine with the sugar and crushed fruit and simmer as in making regular syrup. Remove from heat, skim off foam and pour into clean, half-pint or pint jars. Leave 1/2-inch headspace. Adjust lids and process in a boiling water canner for 10 minutes at altitudes up to 1,000 feet; process 15 minutes at altitudes from 1,001 to 6,000 feet.
Yield: approx. 9 half pints.
Source: University of Missouri Quality for Keeps GH1461, Jam and Jelly Basics. http://extension.missouri.edu/p/GH1461.