01 - In a large, heavy-bottomed pot, combine chopped apples, lemon juice, apple cider, and water. Bring to a simmer over medium heat and cook for about 10 minutes, stirring occasionally, until apples are tender.
02 - Use a potato masher or immersion blender to gently mash the cooked apples, leaving some small pieces for texture.
03 - Stir in granulated sugar, brown sugar, cinnamon, nutmeg, allspice, and salt. Mix thoroughly to dissolve the sugars.
04 - Add unsalted butter cubes and continue cooking on medium heat, stirring often to prevent scorching, until mixture thickens and turns golden caramel, about 20 to 25 minutes.
05 - Bring the mixture to a full boil. Add liquid pectin, stir well, and boil hard for 1 to 2 minutes. Remove pot from heat.
06 - If necessary, skim off any foam. Ladle hot jam into sterilized jars, maintaining 1/4-inch headspace. Wipe rims, affix lids, and process in a boiling water bath for 10 minutes. Adjust processing time for altitude if required.
07 - Allow jars to cool completely. Store in a cool, dark place. Refrigerate after opening.