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 - Using a potato masher or immersion blender, gently mash the softened apples, leaving small chunks for texture.
03 - Add granulated sugar, brown sugar, ground cinnamon, nutmeg, allspice, and salt. Stir thoroughly to dissolve sugars.
04 - Add cubed butter. Continue cooking on medium, stirring frequently, until the mixture thickens and turns a golden caramel color, approximately 20 to 25 minutes. Stir and scrape the bottom to avoid scorching.
05 - Increase the heat to bring the mixture to a boil. Introduce liquid pectin, stir well, and maintain a rolling boil for 1 to 2 minutes. Remove from heat.
06 - If needed, skim off any foam from the surface. Ladle hot jam into sterilized jars, leaving 1/4-inch headspace. Wipe rims, seal with lids, and process in a boiling water bath for 10 minutes. Adjust processing time for altitude as required.
07 - Allow jars to cool undisturbed. Store in a cool, dark place. Refrigerate after opening.