Prepare your rings and sterilize your jars and lids.
In a large pan, combine juice and pectin and whisk well. Add butter or margarine. Bring to a boil over high heat.
As soon as it reaches a full boil, quickly add your sugar and stir well. Stir constantly until the mixture reaches a full rolling boil, let it continue boiling for one minute, and then turn off the heat.
Skim off the foam and start filling your sterilized jars and cap them. Leave it on the counter with minimal air contact on a towel. Once the lids have popped, store the jars in a cupboard for up to a year. Label the jar with the date. Enjoy!