To shape the garlic butter into a roll: If not using immediately, spoon the garlic butter lengthwise onto a sheet of plastic wrap a few inches longer than a stick of butter. Roll the garlic butter up tightly in the plastic wrap. Twist the plastic wrap at each end of the garlic butter (like how a Tootsie roll is wrapped). Holding a twisted end in each hand, roll the log along the work surface to tighten and shape the roll. If the plastic wrap is long enough, tie a knot at each end; otherwise, tie a piece of kitchen twine at each end. Refrigerate or freeze until ready to use (thaw overnight if frozen before using). To use, unwrap and cut crosswise into rounds of garlic butter.