Powdered pectin is mixed with the unheated fruit juice. Liquid pectin is added to the boiling juice and sugar mixture. Purchase fresh pectin each year. Old pectin may result in poor gels. Follow the instructions in the package for the amounts of ingredients and methods of combining them.
Accurate timing is important.
Place in saucepan, add water and bring quickly to a boil. Remove from heat, cover and let stand if desired. Measure mint juice into a large saucepan. Stir in the sugar. Place on high heat, stir constantly and bring to a full boil that cannot be stirred down.