I've got an elm tree down.
Wondering if elm would be a good wood for making charcoal.
just

NO!!!!!

Burn some (This word is unacceptable on Trapperman) elm in a brush pile and that question will answer itself.

Yes!
Good charcoal can be made out of most anything. Once it is done it provides heat to cook, not flavors to food. Thats why you add smoking wood to it.

I ain't saying that it will smell the best while it is burning down to carbon, Depending on the tree, It won't necessarily smell the worst either. If that's what I had, I would go ahead with it.

BTW, there ain't no law saying you can't add a bit of cherry, oak, hickory, whatever to the burn wood, as long as you have to sit and watch it.

You want hard wood like oak,maple.

You didn’t say what kind of elm it is. Red elm is hard and ranks right up there with many other too hard woods btu wise. Chinese elm on the other hand….not so much

Why?

When you are done processing it only the carbon remains.

I have even made it out of pine/fir 2x4's

Not all charcoal is the same. For example, coconut shell charcoal makes a very hard charcoal that does not break down. Just go on a black powder making forum and ask the question, those guys are very particular about what types of wood makes the best charcoal for black powder.
It just depends on what you intend to use it for.

This is correct. I’ve even used charcoal from semi green pine. Its no different than charcoal from hickory, oak, etc…

Lot of times you open a bag of lump and theres all manner of construction debris remnants, they make charcoal with whatevers cheap or free...

Thanks for the info guys/
Used generally for smoking meats. but I have been wanting to try water purification.
just