Colossal Furnace

Updated Description as of 11/5/2026:

Colossal Furnace

An add-on for Jumbo Furnace by Commoble. Build a furnace out of 216 blocks, run it at five tiers (and a secret sixth, Tier 20), and grow its upgrades in its Heart.

Install Ponder to see in-game build guides. (Ponder comes with Create 6.)

• 6×6×6 multiblock. Place 216 Colossal Furnace Blocks as a solid cube and it forms when the last block goes down.
• 512 items at once at Tier 1, up to 1,728 at Tier 5 (all 27 input stacks in one batch), and 8,640 at Tier 20.
• 27 input, 18 fuel and 27 output slots (135 / 90 / 135 at Tier 20, with scroll bars), plus an Upgrade slot and the Heart.
• Hoppers and pipes work on every outside face.
• Lava straight from tanks and pipes. Put a tank from any mod against it, or pipe lava in. No buckets, and it only takes the lava its recipes need.
• Upgrades grow. Put one in the Heart and it slowly turns into the next tier while the furnace cooks.
• Its own furnace screen, whose trim changes colour with the tier.
• JEI and EMI info pages for every item, and its own creative tab.
• With XP Works: a built-in Liquid Experience tank that your pipes can drain.
• With Ponder: animated in-game guides. Hover a Colossal Furnace Block and hold W.
• Every number is configurable.

Building it

1. Fragment Mold (crafting table, reusable):

I S I      I = Iron Ingot
S F S      S = Smooth Stone
I S I      F = Furnace

2. Jumbo Furnace Fragment: in any Jumbo Furnace, smelt 64 Furnaces + 1 Fragment Mold. You get 1 Fragment and the Mold back. Without a Mold, the Jumbo Furnace makes Jumbo Furnaces as usual.

3. Colossal Furnace Blocks: put 8 Fragments in a ring on a crafting table (the furnace shape) to get 8 blocks.

4. Build: place 216 blocks as a solid 6×6×6 cube. Breaking any block gives all 216 back and drops everything inside.

The full furnace costs 13,824 furnaces (110,592 cobblestone). It’s an endgame build.

The five tiers

The item in the Upgrade slot sets the tier. An empty slot means Tier 1.

Unfinished Tier 4 Upgrade (crafting table):

N C N      N = Netherite Ingot
C U C      C = Colossal Furnace Block
N C N      U = Tier 3 Upgrade

Unfinished Tier 5 Upgrade (crafting table):

B S B      B = Block of Netherite
C U C      S = Nether Star
B C B      C = Colossal Furnace Block, U = Tier 4 Upgrade

At Tier 3 and Tier 4 you choose: put the upgrade in the Upgrade slot to run the furnace at that tier, or craft it onward toward the next one.

Tier 20

Put a Tier 5 Upgrade in the Upgrade slot and four bonus slots open under the Heart, one per tier: [Tier 2] [Tier 3] [Tier 4] [Tier 5]. Fill all four with finished upgrades and the furnace becomes Tier 20 (1 + 5 + 5 + 4 + 3 + 2 = 20).

• The input, fuel and output grids scroll (mouse wheel or the scroll bars). The screen stays the same size.
• While any bonus slot is filled, the Tier 5 Upgrade is locked in the Upgrade slot.
• Take a bonus upgrade out and the extra slots freeze: their items are kept (not cooked, not reachable by hoppers) until you put it back.
• The Heart grows +1 per item smelted at every tier, so at Tier 20 it grows 5× faster. Overheat at Tier 20 needs all 90 fuel slots stocked.

The Heart

The Heart holds one Tier 2 Upgrade, Unfinished Tier 4 or Unfinished Tier 5 and grows it into the next tier.

• It grows only while the furnace is cooking: +1 for every item smelted.
• Overheat: with the furnace lit and all 18 fuel slots stocked (90 at Tier 20), growth is twice as fast. The firebox glows brighter and the Heart pulses.
• Targets: 100,000 items for Tier 3, 250,000 for Tier 4 and 500,000 for Tier 5.
• Progress is saved on the item. You can take it out, break the furnace or move it to another furnace without losing anything. Hover it to see Growing: 42,310 / 100,000.
• When it reaches the target, it turns into the next upgrade in place, with a burst of flame.
• Each upgrade does one job at a time, so you can run your furnace on one upgrade while you grow another.

Lava from tanks and pipes

No more buckets. Put a tank from any mod (Mekanism, Create, anything with a fluid tank) against any side of the furnace, or connect a fluid pipe that pushes lava in.

• It takes only what the recipes cooking right now need, a little each tick, never a bucket at once.
• The lava burns straight away. There’s no tank inside the furnace, so nothing burns off while it’s idle, and an idle furnace takes no lava at all.
• Fuel in the fuel slots burns first. Lava fills in once they’re empty, so overheating works as before.
• 1 mB of lava is worth 1/1000 of a Lava Bucket.

Tier 20 lava boost: at Tier 20, one bucket of lava smelts 1,500 items instead of 800, so 50,000 mB smelt 75,000 items. That counts for tanks, pipes and Lava Buckets in the fuel slots. Coal and every other fuel stay the same.

Liquid Experience (with XP Works)

Install XP Works (optional) and the furnace gets a built-in Liquid Experience tank. Without XP Works, nothing changes.

• Smelting XP flows into the tank at 20 mB per XP point. A Liquid XP gauge in the furnace screen shows how full it is (hover it for the amount).
• Pipes are the only way out. Connect any fluid pipe to any side of the furnace and pull it out. No XP can be piped in (only lava goes in, as fuel).

• Tank full? Smelting keeps going and the extra XP is stored the old way (you get it when you take the items out).
• Tier lowered? Nothing is lost. The tank just doesn’t fill again until it’s below the new size.
• Breaking the furnace releases the tank’s XP as XP orbs.

Requirements

• Minecraft 1.21.1 with NeoForge
• Jumbo Furnace 5.0.0.9 or newer (required)
• JEI or EMI (optional, for the info pages)
• XP Works 1.0.0 or newer (optional, for the Liquid Experience tank)
• Ponder (optional, for the in-game guides). It comes with Create 6.
• Install it on both the client and the server.

Config

serverconfig/colossalfurnace-server.toml in your world folder contains each tier’s items at once, cook time and items per coal (Tier 20 included, with its lava boost lava_items_per_bucket), plus the three growth targets, the overheat multiplier and (section xp_tank) the tank size per tier.

Good to know

• The furnace screen is wide. If it doesn’t fit on a small window, set GUI Scale to Auto or one step lower.
• The Upgrade slot, the bonus slots and the Heart are hand-filled only. Hoppers and pipes use the input, fuel and output slots.
• Worlds from earlier versions open fine in 1.4.0. A world saved with 1.1.0 or newer can’t go back to 1.0.0 or older.
• Hoppers move about 2.5 items per second, so the higher tiers are meant for pipes or Create funnels.

Modpacks

You’re welcome to include Colossal Furnace in any modpack.

Credits

Built on Jumbo Furnace by Commoble. Its smelting engine is reused under the MIT license, and Jumbo Furnace is required to play.

This mod, along with all my other mods, is created using AI tools. I develop the ideas, make the design decisions—including what the mod does, how it functions, and how it is balanced—and test every version in-game before release. The code, textures, and art are all generated with AI tools. I carefully review every bug report and suggestion, which directly influence future updates. Due to time constraints, I rely on AI tools to assist in development. If you are opposed to AI-generated mods, this mod may not be suitable for you. I hold the copyright for all images and artwork used in my mods. At this time I also have enabled comments on all of Mod pages If you want to leave any feedback or any ideas you can use this GitHub repository to make a issue slash idea, It will be used for bugs features from you And feedback https://github.com/tyler919/mods/issues