Homemade Butter in a Jar

Pour the cream into the jar, then screw on the lid.

Shake the jar vigorously until butter forms a soft lump, which may take 15 to 20 minutes.

Continue shaking until buttermilk separates from the lump and you're left with a solid butter block and liquid buttermilk.

Place a fine-mesh strainer over a bowl and pour the jar contents through it, draining out the buttermilk.

Transfer the butter block to a piece of plastic wrap, wrap tightly, and refrigerate until needed.