Begin by selecting ripe, juicy peaches. Wash, peel, and chop them into small pieces to measure about 4 cups. Optionally mash for desired texture.
In a large mixing bowl, combine chopped peaches, sugar, and lemon juice. Stir well and let sit for 10 minutes to dissolve sugar and enhance flavor.
In a medium saucepan, combine fruit pectin and water. Bring to a rolling boil over medium heat, stirring constantly. Cook 1-2 minutes until dissolved. Remove from heat and cool briefly.
Pour the pectin mixture into the peach mixture. Stir for 2-3 minutes until well combined and slightly thickened.
Pour the jam into clean, freezer-safe containers, leaving about 1/2 inch space at the top for expansion.
Let containers sit at room temperature for about 24 hours to set, then transfer to the freezer for storage up to 1 year.