01 - In a large, heavy-bottomed pot, combine chopped apples, lemon juice, apple cider, and water. Bring to a simmer over medium heat. Cook for 10 minutes, stirring occasionally, until the apples are tender.
02 - Using a potato masher or immersion blender, gently mash the apples, retaining some pieces for texture.
03 - Add granulated sugar, brown sugar, cinnamon, nutmeg, allspice, and salt. Stir thoroughly to dissolve sugars.
04 - Stir in the cubed butter. Continue cooking over medium heat, stirring frequently, until the mixture thickens and develops a golden caramel hue, approximately 20 to 25 minutes. Scrape the bottom regularly to avoid scorching.
05 - Bring the mixture to a boil. Incorporate liquid pectin, mix well, and boil vigorously for 1 to 2 minutes. Remove from heat.
06 - Skim off any foam if present. Ladle the hot jam into sterilized jars, maintaining 1/4-inch headspace. Wipe jar rims, secure lids, and process jars in a boiling water bath for 10 minutes, adjusting for altitude as necessary.
07 - Allow jars to cool fully before storing in a cool, dark place. Refrigerate after opening.