01 - In a large, heavy-bottomed pot, combine chopped apples, lemon juice, apple cider, and water. Bring to a gentle simmer over medium heat. Cook, stirring occasionally, for about 10 minutes until apples soften.
02 - Using a potato masher or immersion blender, partially mash cooked apples, retaining some small chunks for texture.
03 - Add granulated sugar, brown sugar, cinnamon, nutmeg, allspice, and salt. Stir well to completely dissolve sugars.
04 - Stir in unsalted butter. Continue cooking over medium heat, stirring frequently, until the mixture thickens and develops a golden caramel color, about 20 to 25 minutes. Stir gently and scrape the pot bottom to prevent scorching.
05 - Increase to a full boil. Add the liquid pectin, stirring well. Boil hard for 1 to 2 minutes, then remove from heat.
06 - Skim any foam if present. Ladle hot mixture into sterilized jars, leaving 1/4-inch headspace. Wipe rims, apply lids, and process jars in a boiling water bath for 10 minutes, adjusting for altitude if necessary.
07 - Allow jars to cool completely. Store in a cool, dark place. Refrigerate after opening.