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 apples are tender.
02 - Use a potato masher or immersion blender to gently mash the softened apples, keeping some small chunks for texture.
03 - Add granulated sugar, brown sugar, cinnamon, nutmeg, allspice, and salt. Stir until sugars are fully dissolved.
04 - Stir in butter. Continue cooking on medium, stirring frequently, until mixture thickens and takes on a golden caramel color, about 20–25 minutes. Stir gently and scrape the bottom to avoid scorching.
05 - Bring mixture to a full boil. Add liquid pectin, stirring thoroughly, and maintain a hard boil for 1–2 minutes. Remove from heat.
06 - Skim off any foam if needed. Ladle hot jam into sterilized jars, leaving 1/4-inch headspace. Wipe rims, affix lids, and process jars in a boiling water bath for 10 minutes. Adjust processing time for altitude as necessary.
07 - Let jars cool completely. Store in a cool, dark place. Refrigerate after opening.