Minecraft wiki entry for End_survival, associated text: • Optional: a brewing stand to brew potions for combat while the player takes a recovery break, and bamboo for easy scaffolding structures. However, unlike the above-listed items, potions are not renewable in the End (scaffolding is renewable as it requires bamboo which can be grown indefinitely under enough light level or bone meal and strings which can be obtained as a junk item from fishing) and require the player to import the necessary materials from the Overworld and the Nether beforehand.