Thoroughly wash the apples and let them dry completely before you peel, core and slice them. Use an apple peeler corer slicer for this purpose to save your time. However, if you don’t have the peeler corer slicer, use a simple potato peeler to peel the apples and coarsely chop them with a sharp knife.
Put the chopped apples in the crock pot, filling it up to brim. The apple slices will settle in the pot as they cook and soften.
Combine sugar, cinnamon, cloves and salt in a medium sized mixing bowl and pour this mixture over the apples in the crock pot.
Set the crock pot over the stove on low heat and cook the apples covered for about 10 hours, while stirring occasionally.
As you cook, the colour of the apples will get darker and darker and you will be able to go from stirring with a spoon or spatula to a hand whisk.
The apples will initially release their juice but with time the sauce will begin to thicken. Let the mixture cook down to your desired consistency and taste.
If your apple butter is too thin, you can leave the lid off for the last couple of hours.
Remove the crock pot from the heat and ladle into canning jars, leaving a ¼ inch head space. Remove any bubbles before you put the lid on.
Process the jars in the water bath canner for 10 minutes and store in a cool and dry place.