01 - In a large, heavy-bottomed pot, combine chopped apples, lemon juice, apple cider, and water. Heat over medium and simmer for 10 minutes, stirring occasionally, until apples are tender.
02 - Using a potato masher or immersion blender, gently mash the apples to your preferred texture, leaving some small pieces.
03 - Add granulated sugar, brown sugar, cinnamon, nutmeg, allspice, and salt. Stir until all sugars are fully dissolved.
04 - Stir in butter. Continue cooking over medium, stirring frequently. Allow mixture to thicken and develop a golden caramel color, about 20 to 25 minutes, scraping the bottom regularly to prevent scorching.
05 - Bring mixture to a rolling boil. Add the liquid pectin, mix thoroughly, and boil hard for 1 to 2 minutes. Remove from heat.
06 - If foam develops, skim it from the surface. Ladle the hot jam into sterilized jars, allowing 1/4-inch headspace. Wipe rims, secure lids, and process jars in a boiling water bath for 10 minutes, adjusting for altitude as needed.
07 - Allow jars to cool undisturbed. Store finished product in a cool, dark location. Refrigerate after opening.