Begin by cleaning your canning jars and lids thoroughly with warm, soapy water. Rinse them well and inspect for any chips or bubbles that could compromise their seal. Place the jars upright in a water bath canner or a large pot filled with water, and keep them warm until ready to use.

Rinse the ripe yellow peaches under cool water and pat them dry. Peel, pit, and chop the peaches until you have approximately 2 2/3 cups.

Fill your chosen canner with enough water to cover the jars by at least an inch during processing. Bring the water to a steady boil.

In a large pot, combine the prepared peaches and bottled lemon juice. Sprinkle in the powdered fruit pectin, and bring the mixture to a rolling boil over medium-high heat. Stir constantly and add the granulated sugar after reaching a full boil.

Ladle the hot peach jam into the jar, leaving about 1/4 inch of headspace. Wipe the rim and seal with a lid.

Place the filled jar back into the canner and process the jars in boiling water for 10 minutes.

Carefully remove the jars and allow them to cool completely on a kitchen towel or cooling rack for 12 to 24 hours.