Step 1
Immerse ten 12-ounce jars in simmering water until jam is ready. Wash lids and rings in warm soapy water.
Step 2
Bring a large pot of water to a boil. Add peaches 3 or 4 at a time; cook for 30 seconds. Immerse in ice water for several minutes to stop the cooking process. Drain. Peel off skins core and dice peaches into small pieces.
Step 3
Combine diced peaches sugar raspberries and lemon juice in a large pot. Cook over medium heat stirring occasionally until sugar is dissolved about 5 minutes. Increase heat to medium-high; cook at a rapid boil for 10 minutes. Stir in liquid and powdered pectin; bring back to a boil. Remove from heat and skim foam off the jam with a slotted spoon.
Step 4
Pack jam into hot jars filling to within 1/4 inch of the top. Wipe the rims of the jars with a moist paper towel to remove any food residue. Top with lids and screw on rings.
Step 5
Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil and lower jars 2 inches apart into the boiling water using a holder. Pour in more boiling water if necessary to bring the water level to at least 1 inch above the tops of the jars. Bring the water to a rolling boil cover the pot and process for 10 minutes.
Step 6
Remove the jars from the stockpot and place onto a cloth-covered or wood surface several inches apart until cool 12 to 24 hours. Press the top of each lid with a finger ensuring that the seal is tight (lid does not move up or down at all).