To prepare peppers, remove stems and seeds and chop finely in a food processor. You can vary the proportion of sweet and spicy peppers, or even use entirely sweet peppers, as long as you have a total of 3/4 cups of finely chopped pepper. Pulse cranberries in the food processor as well until finely chopped.
In a bowl, whisk together 1/2 cup sugar and pectin until evenly incorporated.
Combine peppers, cranberries, orange zest and cider vinegar in a heavy saucepan set over medium heat. Cover and simmer, stirring occasionally, for 10 minutes to soften the peppers.
Add calcium water and increase heat to medium-high; bring to a full rolling boil, then whisk in sugar/pectin mixture, stirring vigorously until completely dissolved and mixture returns to a boil.
Stir in remaining sugar and return to a full boil. It should be noticeably thickened.
At this point the jelly can transferred to washed and sterilized jars, and either water-bath processed if desired (see here for full instructions). Otherwise, keep refrigerated for up to 3 weeks or frozen for up to 6 months.
Notes
Calcium powder to make calcium water is included with the Pomona’s brand pectin.