Pour the chilled cream into the mason jar. Make sure the jar is clean and dry.
Tightly seal the lid of the mason jar and shake vigorously for 10-15 minutes, until the cream separates into butter and buttermilk.
Once the butter has been separated from the buttermilk, pour off the buttermilk and discard.
Place the butter in a metal bowl and rinse with cold water for a few minutes, using a metal spoon to press the butter together and release the remaining buttermilk.
Drain the buttermilk and add the salt to the butter. Mix together with a spoon or spatula until the salt is evenly distributed.
Press the butter into a butter dish and serve or store in the refrigerator.
Interesting Facts
Butter has been around for centuries, with the earliest known written reference dating back to 2000 BC.
Butter is a dairy product made from churning cream or milk.
Butter is high in fat and contains vitamins A, D, E, and K.