How to make a blast furnace in Minecraft

The recipe

In a crafting table:

Iron   Iron   Iron
Iron  Furnace  Iron
Stone  Stone  Stone

Five iron ingots, one furnace, and three smooth stone along the bottom. It has to be smooth stone, not regular stone and not cobblestone, which is the step that sends most people to a guide. Our smooth stone guide covers the double smelt that produces it.

What it smelts, and what it refuses

Blast furnaces take ores, raw metals, metal tools and armour, and anything else classed as metal. Iron, gold, copper, ancient debris and chainmail all work, as does melting down an old iron sword into a nugget.

It refuses food, sand, cobblestone, clay, wood and everything else a normal furnace handles. If you want glass or cooked meat you still need the ordinary one, so most bases keep both.

Speed is double, experience is halved per item. Since the total experience for a stack is the same either way and only the rate differs, the trade is almost always worth taking.

Using it as a villager workstation

Placing a blast furnace near an unemployed villager turns them into an armourer, who trades iron and emeralds for armour and, at higher levels, enchanted diamond gear.

Break and replace the workstation to reroll their trades until you get one worth keeping, as long as they have not yet been traded with. Once you trade, the offers are locked for good.

Fuel and automation

It burns the same fuels as a normal furnace and burns through them twice as fast, since it is doing twice the work in the same time. Lava buckets and blocks of coal are the efficient choices for bulk runs.

Automating it works exactly like a furnace: a hopper into the top for input, a hopper into the side for fuel, and a hopper underneath pulling the output into a chest. A row of blast furnaces sharing one input chest will clear a mining trip in the time a single furnace clears a stack.

Many servers with a strong economy make raw ore worth more than the smelted result at certain times, so it is worth checking prices before smelting everything you mine. The survival servers here mostly run a shop where you can see that at a glance.