01 - In a large heavy-bottomed pot, combine chopped apples, lemon juice, apple cider, and water. Bring to simmer over medium heat. Cook for 10 minutes, stirring occasionally, until apples are tender.
02 - Lightly mash the softened apples with a potato masher or immersion blender, leaving small chunks for texture.
03 - Add granulated sugar, brown sugar, ground cinnamon, nutmeg, allspice, and salt. Stir until sugars are fully dissolved.
04 - Stir in the butter. Continue cooking on medium, stirring frequently, until the mixture thickens and caramelizes to a golden hue, about 20–25 minutes. Stir gently and scrape the pot bottom to prevent burning.
05 - Bring to a boil. Add liquid pectin, stir thoroughly, and boil vigorously for 1–2 minutes. Remove pot from heat.
06 - Remove any foam if present. Ladle hot jam into sterilized jars, maintaining 1/4-inch headspace. Wipe rims, secure lids, and process jars in a boiling water bath for 10 minutes, adjusting time for altitude as necessary.
07 - Let jars cool completely. Store sealed jars in a cool, dark environment. Refrigerate after opening.