Wash & remove stems from fruit. Combine with water in a stainless steel saucepan and bring to a boil. Reduce heat, cover and boil gently for 15 minutes. Remove from heat.
Pour prepared mixture into dampened Jelly Bag or cheese cloth lined sieve suspended over a deep container. Let drip to collect juice. For quicker results, squeeze bag; juice may be cloudy.
For jam, press fruit through a sieve to retain as much pulp as possible.
Place 6 clean 250 ml mason jars on a rack in boiling water canner; cover jars with water and heat to a simmer (180F/82C). Set screw bands aside. Heat lids in hot water, not boiling (180F/82C). Keeps jars and lids hot until ready to use.
Measure 3 cups (750ml) chokecherry juice (for jam with pulp) into a large, deep stainless steel saucepan. Stir in sugar and 1/2 tsp butter or vegetable oil to reduce foaming. Over high heat, bring mixture to a full rolling boil. Stirring constantly, boil hard for 1 minute. Remove from heat. Immediately stir in liquid pectin, mixing well. Skim foam. Chokecherries have lots of pectin, so if you wish to omit liquid pectin, just cook the jam longer, ten minutes or so.
