Gather containers: make sure they are clean and dry. Plastic or glass freezer-safe containers will work.

Prep Peaches: Peel and pit peaches (here's my method for how to easily peel peaches). Finely dice peaches and measure exactly 3 cups of diced peaches into a large bowl.

Dissolve Sugar: Add one cup of sugar to the bowl and stir well. Rest for 5 minutes. Repeat with remaining sugar, adding it a little at a time and resting in between, to help the sugar dissolve completely. Stir in lemon juice. Let mixture rest for 10 min. Taste the mixture and if it's still grainy from the sugar don't proceed until the sugar has dissolved! (If needed, you could place the heat-proof bowl or peaches over a saucepan of warm water on the stove. Gently stir the mixture and the heat will help the sugar to dissolve.)

Add Pectin: Whisk water and pectin in a saucepan and bring to a boil, stirring constantly. Boil for 1 minute then remove from heat and whisk into peach mixture. Stir jam constantly for 3 minutes. The jam will start to thicken, and will thicken more as it rests. If it seems overly runny (maybe you had very juice peaches) you can repeat pectin process and add 1/2 or a full additional box of pectin, if needed.

Fill containers, leaving 1/2 inch headspace. Wipe rim of jars clean and cover with lids. Let stand at room temperature for 24 hours before freezing. This allows the jam time to set up, but feel free to enjoy one of the jars right away.

Store jam in the refrigerator for up to 3 weeks or freeze for up to 1 year.