Ring Shake is caused by parasitic bacteria that weaken the wood and results in cracking between and parallel to the trees growth rings resulting in lower strength. This is much like a large straw with a smaller straw inside of it. If it is stood upright it can fall out of the bottom. Ring Shake can also cause a dark discoloration and an unpleasant vinegar or rancid odor. This defect usually occurs in wood with high moisture content. It takes a long time for shake to spread so it is usually found only in the lower part of trees and can be cut out.