Prepare canning supplies. Fill water bath canner to water level according to directions for your canner and place canning basket inside. Begin heating the water in the canner.
Wash canning jars and make sure that they are clean when you begin adding hot jelly to them.
Have rings and jars and a jar lifter ready before you begin.
Wash peppers with cold water and remove stems and seeds. TIP: wear gloves if your peppers are hot ones! Chop the peppers finely with a food processor.
Add vinegar and apple juice and mix together.
***Some recipes recommend that you cover and refrigerate overnight. That produces a hotter jelly. ***I have always just continued and made the jelly without the refrigeration or removing the chopped peppers that some recommend to produce a clear jelly. I love the jam consistency that the peppers provide. Place pepper mixture into a Dutch oven - I love my ceramic lined cast iron Dutch oven.
Add pectin and salt and bring mixture to boil over high , stirring constantly.
Add sugar and stir until all of the sugar has been dissolved.
Bring mixture to a rolling boil that cannot be stirred down and boil hard for one minute.
If foam appears on top, skim off and remove.
Ladle the mixture into clean and hot jars, leaving 1/4 inch headspace.
Wipe the lid with a clean damp paper towel. Add lid and ring.
Add the jars with a jar lifter to the canner. You will want at least an inch of water covering all of the jars when they are all placed in the canner. Cover and bring the water to a boil.
Process jars for 10 minutes. Turn off the heat to the canner and let them sit in the canner for about 5 minutes before removing them.
A great way to let them cool is on a cooling rack over a jelly roll pan to catch any water from the jar.
NOTE: Let them cool for 12 hours before moving them to ensure that they seal properly.
Check lids to make sure that they all sealed. Label and store.