Yes, you will need some form of ice cream maker to make a true sorbet. It serves two purposes: to constantly churn so the sorbet forms small ice crystals instead of large ones, creating a silky texture, and to incorporate air, which is also important for texture and volume. There are many inexpensive ones out there in many forms. You can purchase ones you shake, ones that attach to a stand mixer, old school cranks, or freestanding ones like my Cuisinart Ice Cream Maker