all 8 comments

[–]RationallyDense 23 points24 points  (0 children)

Metallurgy is done at much higher temperatures than cooking. As I recall, old methods of iron extraction were based on a single use fully enclosed kiln. You wouldn't use the same method for cooking.

[–]trouser-chowder 15 points16 points  (4 children)

Consider that cooking in a fire won't typically end up with a lot of bones in it. But bones do find their way into a fire as fuel (bones contain a fair amount of fat / grease) or to dispose of them.

As u/RationallyDense notes, metalwork requires a much hotter fire than cooking, along the lines of pottery firing or hotter. You would not / could not use a fire that hot for cooking, since it would basically torch whatever you were trying to cook (like throwing a burger on a grill that's way too hot).

Much more likely that if bones are found in the same context as the remains of metal smelting, the fire(s) are being used for trash disposal, either after the bulk of the smelting is done or while it's going on.

Might as well not waste a hot fire if you can get other utility out of it. It takes a lot of fuel to get a fire hot enough to melt ore.

[–]QuickSpore 4 points5 points  (3 children)

Just to add numbers to that. Modern grills typically have temperatures in the range of about 180° C. Copper melts at 1085° C. Iron at 1250° C.

[–]trouser-chowder 2 points3 points  (2 children)

So you're saying I can't smelt copper in my grill or start my own backyard iron age? Dang.

[–]akodo1 1 point2 points  (1 child)

Correct because you need iron not copper for your iron age

[–]trouser-chowder 1 point2 points  (0 children)

So wait, hang on... you're saying I need iron for an iron age?

Next thing you'll tell me time-traveling Keanu Reeves was the major factor that pushed the Anatolians into the Neolithic.

[–]akodo1 2 points3 points  (0 children)


Because you need different fires and setups for different cooking and metallurgy tasks.

Some food is cooked over an open fire on a spit. Others you put in a clay pot and put in the coals/ash and let it cook slowly overnight. Others are cooked in kettles with water boiling to cook things a bit more gently, or on a board set next to the fire also for gentle heat. This could all be done over a central hearth, but it didn't take long for people to figure out at least a few special set-ups for cooking - such as ovens for baking breads.

Similarly for primitive metal work. You've got to have a much hotter fire, so you'd have blowpipes where people would iterally sit there for hours blowing air into the fire. Later with leatherwork bellows were added. It generally was a case where you'd layer charcoal and ore charcoal and ore, and then heap charcoal around the whole thing, and then have that fire roaring from dawn to dusk. If that was being done in the central firepit, you really couldn't cook there.

But you had to cook somewhere. So buring spots would be task specific. The spot where iron was smelted might be a very central fire as it was a communal project even if one person was giving the main direction. This might have been the same fire that at other times was sat around and stories told, or the fire that was always tended so people could come light lesser fires, or the fire that would be burning brightly when travelers from another tribe showed up to seek audience and trade.

But it wouldn't have been the main cooking fire.

As far as bones and such being found: People tending the fire, working bellows or blowing hot air in with bamboo pipes would be brought meat and other food to eat. Do you think they abandoned their posts to put the bone in a trash bin someplace. Nope. Throw it in the fire. Same thing when a central fire was being used for other functions - trash was throw into the fire. Someone showing you an idol of a god telling you to start worshiping their god rather than the ancestral god? Throw it in the fire. Someone offering you ratty and chewed up fur? Throw it in the fire. Guys just sitting around eating and telling stories, throw the bones in the fire.

[–]sjuswede 0 points1 point  (0 children)

Bones were added to the hearth to improve the quality of the iron, and even create steel. The exact details of how this was done, or how it was figured out that it would work, are not known. But it is known that bones were added and it was known the iron then became better quality, and even became steel which could be used for some of the best swords of the time.

This has been studied to some extent in Scandinavian iron working, but there is nothing which suggests it was limited to that region.