shirring head 14 can be used to determine the shirred pack ratio or density of the stick at a slow rate the shirred pack ratio will be higher than at a faster rate it is known in the art to twist or rotate the shirred stick about its longitudinal axis during shirring and advantages of such twisting is disclosed in u s pat no 3 454 981 among others if twisting the stick is desired it can be accomplished by rotating the sleeve 26 by any suitable means not shown as it is being moved longitudinally through the shirring head 14 since the pleats are formed tight to the sleeve rotation of the sleeve will cause the stick to twist as it is being shirred shirring and the controlled longitudinal withdrawal of sleeve 26 continues until a desired length 44 of shirred casing has accumulated on the sleeve fig2 at this point shirring is stopped and the shirred length of casing 44 is separated from the unshirred casing 42 separation can be accomplished manually or by any suitable mechanical means which tears or cuts the casing in one separation method as shown in fig3 the first end 27 of the sleeve is moved beyond a cutting means 34 the cutting means 34 such as a blade is then moved through the casing to severe it at a point intermediate the shirring head 14 and the end 27 of sleeve 26 in order to transfer the severed length 44 of shirred casing from the sleeve sleeve gripper 30 and clamp 22 are opened fig4 transfer from the sleeve to.