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 10 minutes, stirring occasionally until apples are tender.
02 - Gently mash the apples using a potato masher or immersion blender, leaving some texture with small chunks.
03 - Add granulated sugar, brown sugar, cinnamon, nutmeg, allspice, and salt. Stir until sugars dissolve completely.
04 - Stir in cubes of unsalted butter. Continue cooking over medium heat, stirring frequently and scraping the bottom, until the mixture thickens and turns a golden caramel color, about 20–25 minutes.
05 - Bring the mixture to a boil. Add liquid pectin, stir well, and boil hard for 1–2 minutes. Remove from heat.
06 - Skim off any foam as needed. Ladle hot jam into sterilized jars, leaving 1/4-inch headspace. Wipe rims clean, 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 sealed jars in a cool, dark place. Refrigerate after opening.