How to Build an Automatic Super Smelter

A super smelter uses multiple furnaces in parallel to smelt large quantities of items quickly. Instead of waiting for one furnace to process a stack, 8 or 16 furnaces work simultaneously, processing an entire inventory in seconds. The design is purely hopper-based with no redstone required, making it one of the easiest high-value builds in the game.

Why build a super smelter?

• Smelt a full inventory of ore in under a minute.
• Process food in bulk (smoker variant).
• XP storage: smelted items store XP in the furnace until manually extracted.
• No redstone knowledge needed, purely hopper mechanics.

Furnace types

Furnace Type	Speed	Items Smelted
Regular furnace	10 seconds per item	All smeltable items
Blast furnace	5 seconds per item	Ores and metal gear only
Smoker	5 seconds per item	Food items only

Blast furnaces and smokers are twice as fast as regular furnaces but limited in what they process. For a general-purpose smelter, use regular furnaces. For dedicated ore processing, use blast furnaces. For food, use smokers.

Materials (8-furnace super smelter)

Item	Quantity	Notes
Furnaces (or blast furnaces/smokers)	8	Core smelting units
Hoppers	24	8 input + 8 fuel + 8 output
Chests	6	Input, fuel, and output storage
Building blocks	~30	Frame

Step-by-step build instructions

Step 1: Place the furnace row

Line up 8 furnaces in a straight row. Leave space above, behind, and below each furnace for hoppers.

Step 2: Add input hoppers on top

Place a hopper on top of each furnace. These feed items into the furnace's input slot. Connect all 8 top hoppers in a chain (each pointing into the next) with a double chest at one end. When you dump items into the chest, they flow through the hopper chain and distribute across all furnaces.

Top-down view:

  [Chest] -> [H] -> [H] -> [H] -> [H] -> [H] -> [H] -> [H] -> [H]
              |      |      |      |      |      |      |      |
             [F]    [F]    [F]    [F]    [F]    [F]    [F]    [F]

H = Hopper (pointing left in chain, but also feeding down into furnace)
F = Furnace

Each hopper in the chain tries to push items into the furnace below it. If the furnace's input slot is full (1 stack), the hopper passes items along the chain to the next hopper. This naturally distributes items evenly across all 8 furnaces.

Step 3: Add fuel hoppers on the side

On one side of each furnace, place a hopper feeding into the furnace's fuel slot. Connect these 8 side hoppers in a chain, ending at a fuel chest. Load the fuel chest with coal, charcoal, dried kelp blocks, or any fuel. The chain distributes fuel to all furnaces.

Step 4: Add output hoppers below

Below each furnace, place a hopper pointing toward a collection line. Chain all 8 bottom hoppers together, ending at an output double chest. Smelted items are pulled from the furnaces and flow to the output chest.

Side view of one furnace unit:

  [Input Hopper]   (from chain above)
  [Furnace] <-- [Fuel Hopper]  (from side chain)
  [Output Hopper]  (to chain below, into output chest)

Step 5: Scale up (optional)

Double the design to 16 furnaces for twice the throughput. The hopper chain length is the only limit, as hoppers transfer 2.5 items per second regardless of chain length.

Throughput calculations

• 1 regular furnace: 1 item every 10 seconds = 6 items/minute
• 8 regular furnaces: 48 items/minute = ~2,880 items/hour
• 16 regular furnaces: 96 items/minute = ~5,760 items/hour
• 8 blast furnaces: 96 items/minute (ores only)

The hopper transfer rate (2.5 items/second) exceeds the input demand of 8 regular furnaces, so the hoppers are not a bottleneck until around 25+ furnaces.

Fuel efficiency

Fuel	Items Smelted	Notes
Coal / Charcoal	8	Standard, easy to obtain
Coal block	80	Most efficient stackable fuel
Dried kelp block	20	Renewable, great with kelp farm
Blaze rod	12	Good if you have a blaze farm
Bamboo block	1.5	Renewable but low efficiency
Lava bucket	100	Highest per item, but not stackable

XP farming with the smelter

Every item smelted stores XP in the furnace. If you extract items via hopper, the XP stays in the furnace. To collect stored XP, break the output hopper temporarily and pull one item from the furnace manually. All accumulated XP releases instantly. For dedicated XP farming, smelt cheap items (cactus, cobblestone, kelp) and collect the XP periodically.

Common mistakes

• Hopper pointing wrong direction. Each hopper must point into its furnace (top into input, side into fuel, bottom pulling from output). Shift-click the furnace while placing the hopper to ensure correct orientation.
• Uneven distribution. If the first furnace in the chain is always full and the last one is empty, your input rate is lower than the smelting rate. This is normal and means the system is working. Items distribute as the first furnaces fill up.
• Running out of fuel. Keep the fuel chest stocked. Without fuel, all 8 furnaces stall simultaneously. Set up a dedicated fuel farm (bamboo, kelp, or charcoal) to keep the supply constant.
• Using blast furnaces for non-ore items. Blast furnaces only smelt ores and metal items. They reject food, clay, sand, and logs. Use regular furnaces or smokers for those.

Frequently asked questions

Is 8 furnaces enough?

For most survival players, 8 furnaces handle all smelting needs. If you run a large farm that produces thousands of items per hour (like a cactus farm), expand to 16 or 32.

Can I use this to smelt XP efficiently?

Yes. Cactus and kelp are the most popular XP smelting items because they are farmable in unlimited quantities. A cactus farm feeding an auto smelter is the classic "XP bank" design.

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