Step 3
Place the plums, pineapple, apple juice, orange juice concentrate, and lemon juice into a large pot over medium-low heat, cover, and cook until the plums are soft, 15 to 20 minutes. Mash the plums and pineapple with a potato masher until thoroughly broken up, but leave small chunks of fruit in the mixture. With the fruit mixture at a slow simmer, stir in the cloves, allspice, pectin, and butter (to reduce foaming). Raise heat to high and bring the mixture to a full, rolling boil for 1 minute, stirring constantly. Mix in the sugar, stirring constantly, and cook for 1 more minute at a full, rolling boil. Remove from heat, stir in red food coloring until even in color, and skim off any foam.