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 become tender.
02 - Lightly mash the apples with a potato masher or immersion blender, leaving a few small chunks for body.
03 - Add granulated sugar, brown sugar, ground cinnamon, nutmeg, allspice, and salt. Stir thoroughly until the sugars dissolve.
04 - Stir in butter cubes. Cook over medium heat, stirring often, for 20–25 minutes until the mixture thickens and develops a golden caramel hue. Take care to scrape the bottom to prevent scorching.
05 - Bring the mixture to a rolling boil. Add liquid pectin, stir thoroughly, and continue boiling rapidly for 1–2 minutes. Remove from heat immediately.
06 - If foam forms, skim it from the surface. Ladle hot jam into sterilized jars, allowing 1/4-inch headspace. Wipe the rims, secure lids, and process jars in a boiling water bath for 10 minutes, adjusting for altitude as necessary.
07 - Allow jars to cool undisturbed. Store finished jam in a cool, dark area. Refrigerate after opening.