You can enchant your furnace, using an enchanting table or an anvil. Enchantments Efficiency (DIG_SPEED) Increases smelting speed. Stock is 10 seconds per smelt. Modified time in seconds is 20/(level + 2). Maximum level that will impact performance is 99. lvl 1 = 6.7s lvl 2 = 5s lvl 3 = 4s lvl 4 = 3.3s lvl 5 = 2.9s Unbreaking (DURABILITY) Increases smelting time. Stock varies by fuel. Time = default time * (level / 5 + 1) Ex. Coal burns for 80 seconds. Unbreaking 1 -> 96 seconds. Fortune (LOOT_BONUS_BLOCKS) Adds additional result chances. lvl 1 = 33% chance lvl 2 = 25% chance per level lvl 3+ = 20% chance per level Silk Touch (SILK_TOUCH) Furnace remains lit but will preserve remaining burn time when it has nothing to smelt. Does not save paused time when broken and replaced.