This is some of the worst lump charcoal I have ever dealt with. A large proportion of the wood appears to be various types of pre-milled wood and I can only hope that it was unprimed. It burns with enough ash to make it nearly useless for anything but a quick steak, which is about all the time you have as it burns very quickly compared to other lump that have used. There are far too many "fines" and dust in the bag and virtually none of the contents are the size of "lumps" (my four bags were packed in an original sealed box, from Lowe's, so should have not suffered extensive shipping damage).
The following comments are not factored into my review and are based on information at http://www.nakedwhiz.com/lumpdatabase/lumpbag6.htm
There have been reports of plywood (contains glue which creates who knows what when it burns) and other strange items in the bag, including multiple reports of what was believed to be the fibrous ceramic insulating lining of the kiln.
It is stated that "For those of you interested in these things, the June, 2003 issue of Gourmet magazine indicates that Cowboy produces the lump sold as Martha Stewart, Whole Foods and Williams Sonoma. And of course, we already knew that Genuswine Lump is also Cowboy."
Note also that the "Naked Whiz" review finds that the ash levels are very low, in contrast to my experience.