Coffee does make a great organic stain. When my wife and I re did our kitchen, I made a cutting board above the dishwasher opening using oak. I wanted to match the cabinet color as closely as possible, and didn't want to use the lacquer stain I got from the cabinet company. I boiled the grounds, and the resulting juice was my stain. The board still maintains its original look after about twenty years. Tobacco juice and walnut husks also make good stains.
This topic was discussed not too long ago, and many suggested using real dirt. After all, what's closer to nature then the real thing? I've read that the dirt should be baked in the oven to kill any organic critters that might call it home.
Don
