This is the way my Gramdmother made Cantaloupe Butter. She used the cooked Canaloupe and mixed it into fresh churned butter. I remember she added maybe three tablespoons of the cooked Cantaloupe to one pound of butter. I love this on hot bread. I just use quality store bought butter to make mine.
Pare the cantaloupe, remove seeds and cut into 1x2 inch squares. Dissolve the alum in the water and bring to a boil. Add the cantaloupe and cook for 15 minutes. Drain well. Combine vinegar, sugar and spices. Add the cantaloupe and simmer until fruit is transparent.(about 45 minutes). Place in hot sterilized jars and seal.