A new and distinct cultivar of Hydrangea plant named ‘SCHROLL85-09-02’, characterized by its compact, upright and mounded plant habit; moderately vigorous growth habit; freely branching habit and strong stems; dark green-colored leaves; large mophead-type inflorescences with red purple-colored sterile flowers; when “blued”, that is, treated with aluminum sulfate, sterile flowers are purple in color; long flowering period; and good postproduction quality and longevity.