Back in early March a neighbor had a small elm taken down, and I took the opportunity to conduct a drying experiment. I oven-dried a sample slice, weighing it before and after, and established the initial moisture content at 76%. I also weighed a medium-sized split, and have continued weighing it every week or so, regularly calculating the average moisture content. Today that split of elm hit 20%.
![American elm, fresh-cut to 20% in 103 days American elm, fresh-cut to 20% in 103 days](https://www.hearth.com/talk/data/attachments/105/105124-e00258a8f0134681c6ee85143bb0e514.jpg)
This method is much more accurate than an electronic meter, but the result probably isn't typical; the split was sitting on top of a stack in a very sunny spot, only about three feet from a SE-facing brick wall that holds a lot of heat. Also, 20% is the average moisture content. It may be 10% on the outside and 27% in the middle, but overall it's 20%. For comparison I'm also tracking the drying of one split each of red oak, white oak and mulberry. None of those is ready to burn quite yet.
![American elm, fresh-cut to 20% in 103 days American elm, fresh-cut to 20% in 103 days](https://www.hearth.com/talk/data/attachments/105/105124-e00258a8f0134681c6ee85143bb0e514.jpg)
This method is much more accurate than an electronic meter, but the result probably isn't typical; the split was sitting on top of a stack in a very sunny spot, only about three feet from a SE-facing brick wall that holds a lot of heat. Also, 20% is the average moisture content. It may be 10% on the outside and 27% in the middle, but overall it's 20%. For comparison I'm also tracking the drying of one split each of red oak, white oak and mulberry. None of those is ready to burn quite yet.