Today, we’re canning butter into pint jars. After canning, it’s got a 3-5 year shelf life and that keeps it out of our freezers, so we’ve more room for other things.
Training video:
https://youtu.be/zmrw_O0_hW4
And a spot that you can print out the directions (and includes how to make butter, as well):
https://www.survivopedia.com/make-can-homemade-butter/
You will not find a recipe for how to do this in the typical recipe books.