01 - Place all berries, grated apple, and orange zest (if used) into a large, heavy-bottomed saucepan.
02 - Stir in the granulated sugar and lemon juice. Mix thoroughly and let the mixture sit for 10 minutes to macerate.
03 - Set the saucepan over medium heat and bring the mixture to a gentle boil, stirring frequently to avoid sticking.
04 - Lower the heat and simmer for 25 to 30 minutes, stirring often until the fruit breaks down and the mixture thickens.
05 - For a firmer consistency, sprinkle in the powdered pectin and cook for an additional 5 minutes, stirring constantly.
06 - Test jam by placing a spoonful on a chilled plate; if it wrinkles when pushed, it is ready.
07 - Remove from heat and skim off any foam. Ladle hot jam into sterilized jars, leaving ¼-inch headspace, then seal immediately.
08 - Allow jars to cool. Refrigerate and use within one month, or process in a boiling water bath for 10 minutes to store unrefrigerated.