When you make the recipe, in the left-hand panel select "Smelting" for the recipe type and "Minecraft" for the recipe namespace. The namespace really only matters if you're making a recipe for an already existing item - "Mod" means that it's a brand new recipe, and "Minecraft" means that it's replacing the current one.
When you make the recipe, in the left-hand panel select "Smelting" for the recipe type and "Minecraft" for the recipe namespace. The namespace really only matters if you're making a recipe for an already existing item - "Mod" means that it's a brand new recipe, and "Minecraft" means that it's replacing the current one.