Recipe yields 3 half-pint jars.

Prepare for Canning

• Prepare the calcium water: Combine ½ teaspoon calcium powder (from the small packet in the box of Pomona’s pectin) with ½ cup water in a small jar. Screw on a lit and shake until well-combined. You'll have more than you need for this recipe. Store the excess in the refrigerator for use in making additional jam or jelly recipes.
• Wash the jars you'll use, making sure each is clean and free of nicks in the rim, which could impede sealing.
• Wash the lids and rings in hot soapy water. (If you're using non-Ball brand lids, prepare as suggested by manufacturer.)
• Place empty jars in a canning pot or large stock pot with enough water to cover by an inch or two, cover pot, and set on high heat. It can take awhile for the water to heat, so get it started before you begin making the recipe.

Prepare the Jelly

• Remove stems and seeds from bell pepper and finely dice. Remove stems from jalapeño peppers; removing seeds and membranes is optional. Leaving them in will add more heat to the jelly. You can chop with a knife or pulse the peppers in a food processor. Measure the peppers after chopping.
  2/3 cup green bell pepper, 2/3 cup jalapeño peppers
• Transfer chopped peppers to a large saucepan and add vinegar and calcium water. Heat to a boil, then simmer for 5 minutes.
  1 1/3 cup distilled vinegar, 2 teaspoons calcium water
• While peppers are cooking, combine 1/2 cup of the sugar with the pectin and stir well.
  2 1/3 cups granulated sugar, 1 1/2 teaspoons pectin
• Add calcium water to the hot mixture and stir to combine.
• Add sugar and pectin mixture, stirring vigorously for a minute or two to dissolve pectin. Add the rest of the sugar and return to a full boil; remove from heat. 

Process the jars

• While mixture is returning to a boil, remove the empty jars from the canner, draining the water back into the pot.
• Ladle hot jelly into prepared jars, leaving a 1/4" headspace.
• Wipe jar rims to remove any residue. A clean rim is essential to a good seal.
• Set jar lids in place. Screw bands on finger tight.
• Use a jar lifter to gently submerge jars into hot (180°F) water in the canning pot. Water should cover the top of the jars by two inches. The water will cool somewhat in reaction to the addition of the jars. Return the water to a boil and set the timer.
• Process jars for 10 minutes at 0-1,000' feet altitude. Add an additional 1 minute to the processing time for every 1,000 foot above sea level.
• Remove jars from water using the jar lifter and transfer to a solid, towel-covered surface. Allow to cool for 12-24 hours.
• Check seals. Lids should be solid and pulled down tight. (if they flex and pop, the jar didn’t seal; put unsealed jars in the refrigerator and use those first).
• Remove rings and wash outsides of jars. Label and store in a cool, dry place for up to a year.