Gather ripe peaches, sugar, lemon juice, and optional pectin
Wash the peaches
Peel, pit, and chop the peaches
Mash or blend the peaches to your preferred texture
Combine peaches, sugar, and lemon juice in a large pot
Add pectin if using, following the package instructions
Bring the mixture to a boil over medium-high heat
Stir constantly to prevent sticking
Boil until the jam thickens and reaches the setting point
Test the jam for doneness
Remove the pot from the heat
Skim off any foam if needed
Ladle the hot jam into sterilized jars
Leave proper headspace
Wipe the jar rims clean
Seal with lids and rings
Process the jars in a boiling water bath if preserving
Let the jars cool completely
Check that the lids have sealed
Store sealed jars in a cool, dark place
Refrigerate any unsealed jars and use them first