You’ll need to have a plastic or glass jar (try a baby-food container), plus a marble or small wooden bead (mine was 16 mm).
All you have to do is pour some cream into the jar about 1/3 of the way full, add a shake or two of salt if desired, and place the marble or wooden bead into your jar.
Then replace the lid tightly and shake shake shake!!! Shake it until the bead or marble stops to move around. It took me about 5 minutes.
Yum yum! Remove the marble or bead, and label the jar. You can chill it in the fridge before serving if you want it a little harder. Store leftovers in the fridge as well.
You can download the homemade butter labels here.
Source: A Lemon Squeezy Home