The ornamental design for a steppedinterior for a beverage jug, as shown and described.
FIG. 1 is a front side perspective view of my stepped interior for a beverage jug;
FIG. 2 is a cross-sectional view thereof taken through section 2—2 of FIG. 3; and,
FIG. 3 is top plan view thereof.
The broken line showing is for illustrative purposes only and forms no part of the claimed design. The sectional view is provided to better show the contour or configuration of the exterior surface of the interior of the claimed design.