01 - In a large heavy-bottomed pot, combine chopped apples, lemon juice, apple cider, and water. Bring to a simmer over medium heat and cook for about 10 minutes, stirring occasionally, until apples are tender.
02 - Use a potato masher or immersion blender to slightly mash the apples, leaving small chunks for texture.
03 - Add granulated sugar, brown sugar, ground cinnamon, ground nutmeg, allspice, and salt. Stir thoroughly to dissolve sugars.
04 - Mix in unsalted butter cubes. Cook on medium heat, stirring frequently and scraping the bottom, until the mixture thickens and develops a golden caramel color, about 20 to 25 minutes.
05 - Bring the mixture to a rolling boil. Add liquid pectin, stirring well, and boil hard for 1 to 2 minutes. Remove from heat.
06 - Skim off any foam. Ladle hot jam into sterilized jars, leaving 1/4-inch headspace. Wipe rims, apply lids, and process in a boiling water bath for 10 minutes; adjust time for altitude as needed.
07 - Allow jars to cool completely on a towel or rack. Store sealed jars in a cool, dark place. Refrigerate after opening.