The design is the features of shape, configuration and ornament of the portions of the beverage extractor as shown in solid lines in the drawings. The portions shown in stippled lines do not form part of the design.Drawings of the design are included.FIG. 1 is a left side view of a BEVERAGE EXTRACTOR showing the design, the right side view being a mirror image of FIG. 1;FIG. 2 is a front elevation view of FIG. 1;FIG. 3 is a rear elevation view of FIG. 1;FIG. 4 is a top plan view of FIG. 1;FIG. 5 is a bottom plan view of FIG. 1;FIG. 6 is a top, front, left side perspective view of FIG. 1, the top, front, right side perspective view being a mirror image of FIG. 6; andFIG. 7 is a top, rear, left side perspective view of FIG. 1, the top, rear, right side perspective view being a mirror image of FIG. 7.