01 - Combine chopped apples, lemon juice, apple cider, and water in a large heavy-bottomed pot. Bring to a simmer over medium heat and cook for about 10 minutes, stirring occasionally, until apples are tender.
02 - Using a potato masher or immersion blender, lightly mash the apples while leaving small chunks for a textured jam.
03 - Add granulated sugar, brown sugar, ground cinnamon, nutmeg, allspice, and salt to the pot. Stir thoroughly until sugars are fully dissolved.
04 - Stir in unsalted butter. Continue to cook on medium, stirring frequently and scraping the bottom, until the mixture thickens and turns a rich caramel color, about 20 to 25 minutes.
05 - Bring the mixture to a vigorous boil. Stir in the liquid pectin and boil hard for 1 to 2 minutes before removing from heat.
06 - Skim off any foam as needed. Ladle hot jam into sterilized jars, maintaining 1/4-inch headspace. Wipe the rims, secure lids, and process in a boiling water bath for 10 minutes. Adjust time for altitude as necessary.
07 - Allow jars to cool completely without disturbance. Store in a cool, dark place. Refrigerate after opening.