I've got a bunch from ageing Chardonnay. They drop these into the big tanks until they get the right flavor then yank them out. They are French Oak and covered with mold and stuff. I clean them off with a planer and either smoke with them or put some nice decoration on my smokehouse. The French Oak is the dark wood. No stain or coloring on that wood. It's just the way it looks. Smells great too!