Minecraft wiki entry for Twisting_Vines, associated text: Twisting vines can be obtained with any tools. They are broken instantly using any tool. They have a 33% chance to drop a single twisting vine when broken, increased to 55% with Fortune I, 77% with Fortune II, and 100% with Fortune III (or higher). They always drop a single twisting vine when broken with shears or with a tool enchanted with Silk Touch. Any segments left unsupported from below break with a 33% drop chance, regardless of tool used. Accordingly, twisting vines are best harvested from the top.