How about weighing the timber and comparing it to a known dry weight?

I am starting to stock pile brace stock for future use. And more importantly, naturally curved stock would be nice to select from. As I walk around my mill yard I can point out the dryer piles, they are grayer.

While on the topic of dry timber, I recently uncovered a pile of timber, it had a tarp over it, there was more ice on the covered timber than an uncovered pile. I just swept the dry snow off the uncovered pile, I will be scrapping ice off the covered timbers. I suspect moisture from the ground could not escape the tarp and froze on the timber, and or some of that free moisture coming out of the timber got stuck under the tarp. It was not covered all the way to the ground, either.