Wash and clean the mason jars before use; it is recommended to sterilize using a hot water boil. Keep the mason jars in hot water and so the same with the sealing caps.
Cook the fruit with the orange juice and the zest in a medium sized pan, when the fruit is fully cooked blend together using an immersive blender or a stand-up blender.
Add the cooked fruit again to the pot and place in the stove to continue the cooking process. Add the fruit pectin and stir well, add the butter to reduce foaming, if any foams forms remove with a spoon.
Bring mixture to a full rolling boil on high heat and continue stirring. Add the sugar, stir to combine and boil for another minute. Do not diminish the amount of sugar as the pectin won't set.
Ladle the jam immediately into the warm sterilized jars and fill within 1/4 inch of top. Do not add more than necessary. Clean the rims of the jars with a clean paper towel and place the two lids. First the sealing one and then the closing one.
Make sure the water bath is hot before starting the sealing process. Place the jars on the elevated rack included in the canning pot. Lower the rack into the boiling water making sure the water covers the jars at least 2 inches. Cover and boil for 10-15 minutes. Remove the jars using the proper utensil and place upright on a towel to cool completely.
After doing this you will start hearing the lid popping, that means the process was successful, and the jars are sealed. After the jams are cool press the center of the lid with your finger, if it pops up that means the jar is not sealed correctly, and that container must be refrigerated or reprocessed to achieve a correct seal.
Store the unopened jars in a cool, dry, dark place up to six to 12 months. Opened jars may last up to three weeks inside the fridge.