Step 1
Heat five 12-ounce jars in simmering water until ready for use. Wash lids and rings in warm soapy water.
Step 2
Mix peaches sugar lemon juice cinnamon nutmeg and allspice in a large pot. Bring to a boil; cook stirring occasionally until peaches are soft about 15 minutes. Remove from heat.
Step 3
Mash peaches with an immersion blender or potato masher to desired size and texture. Return to the heat; continue cooking jam until thickened about 10 minutes more.
Step 4
Pack jam into hot jars filling to within 1/4 inch of the top. Wipe rims with a clean damp cloth. 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 in jars using a holder placing them 2 inches apart. Pour in more boiling water to cover the jars by at least 1 inch. 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 about 12 hours. Press the top of each lid with a finger ensuring that lid does not move up or down and seal is tight.