Pour everything into a glass jar, stir gently
Cover with a breathable lid or cloth
Let it sit at room temperature for 12 to 24 hours
Pour fermented cream into a stand mixer with the whisk attachment
Whisk on low to medium until the cream separates (around 5-8 minutes)
Strain the buttermilk into a separate jar
Rinse the butter under cold water and squeeze out excess buttermilk
Shape, wrap in parchment, refrigerate
