Fill a Canner half-full of water and bring to a simmer over medium-high heat.
Wash Mason Canning Jars, Lids and Bands in hot, soapy water and then rinse with warm water. Add jars, screw bands and lids to simmering water. Let stand in hot water until ready to use. Drain well.
Remove the skin from the peaches by blanching for 45 seconds in boiling water, then removing and placing in ice cold water for 1 minute. Using a sharp paring knife, make a crisscross slit at the bottom of the peach to create a place to insert the knife blade. Gently grab the skin between your finger and the knife blade and remove the skin (see photos above). Once skin is removed, remove the pits. Finely chop the peeled, pitted peaches.
Measure 4 cups finely chopped peaches and cook over medium-high heat in 6- or 8-quart saucepan. Add lemon juice to the peaches and stir to combine. Add sugar to saucepan and stir to combine. You may add 1/2 tsp. unsalted butter to reduce the foaming if you wish.
Bring mixture to full rolling boil on high heat, stirring constantly. Stir in pectin pouch quickly. Return to a full rolling boil and boil for exactly 1 minute, stirring constantly. Be careful not to let mixture boil over. Remove from heat and skim off any foam with a metal spoon.
Ladle mixture into the prepared, cleaned jars. I really recommend using a Wide-Mouth Funnel to easily ladle mixture into jars. Fill each jar to within 1/8-inch from the top. Wipe the jar rims and threads and cover with 2-piece lids. Screw bands on tightly and place jars on elevated Canning Rack in canner. Lower rack into canner so that water covers jars by 1 to 2 inches. If more water is needed, add boiling water. Cover and bring to gently boil for 10 minutes. Remove jars using a Jar Lifter and place upright on a towel to cool completely. After jars cool, check seals by pressing middle of the lid with your finger. If lid springs/pops back, it is not sealed and that jar will need to be refrigerated.
Let stand at room temperature for 24 hours. Store unopened jam in a cool, dry, dark place for up to 1 year. Refrigerate opened jams for up to 3 weeks.