While your apple butter is cooking, wash half-pint jars (jelly jars) or pint jars in hot soapy water, rinse, and keep warm. We like to place ours on a baking sheet in a lower temp oven to stay hot.
Once you've mashed up the apples, promptly ladle or pour the resulting apple butter mixture into the hot jars you prepared ahead of time. This is where a funnel pitcher comes in super handy. Be sure to leave about a 1/2-inch gap at the top of each jar.
Wipe the rim of each jar with a wet towel or rag, place the lid on, and tighten the band.
Then place the hot jars down in a boiling hot water bath canner with 1-2 inches of water over the jars, and process those jars in the hot water bath for about 20 minutes.
Allow your jars to rest for at least 24 hours, but be sure to check every lid to make sure it's sealed shortly after canning.
Before moving to the pantry, write what it is and the year on the lid, so you know when you made it.