- 10 apples, peeled, cored, and chopped
- 1 cup white sugar
- 2 teaspoons ground cinnamon, or more to taste
- 1/2 teaspoon ground cloves (optional)
- 1/4 teaspoon ground nutmeg
- 8 half pint canning jars with lids and rings
- Cook apples in slow cooker on Low until apples are very soft, about 18 hours.
- Puree apples in a blender or food processor; return pureed apples to the slow cooker. Stir sugar, cinnamon, cloves, and nutmeg through the pureed apples.
- Continue cooking on Low until thick, about 4 hours.
- Sterilize the jars and lids in boiling water for at least 5 minutes. Pack the apple butter into the hot, sterilized jars, filling the jars to within 1/4 inch of the top. Run a knife or a thin spatula around the insides of the jars after they have been filled to remove any air bubbles. Wipe the rims of the jars with a moist paper towel to remove any food residue. Top with lids, and screw on rings.
- Place a rack in the bottom of a large stockpot and fill halfway with water. Bring to a boil and lower jars into the boiling water using a holder. Leave a 2-inch space between the jars. Pour in more boiling water if necessary to bring the water level to at least 1 inch above the tops of the jars. Bring the water to a rolling boil, cover the pot, and process for 10 minutes.
- Remove the jars from the stockpot and place onto a cloth-covered or wood surface, several inches apart, until cool. Once cool, press the top of each lid with a finger, ensuring that the seal is tight (lid does not move up or down at all). Store in a cool, dark area.