Do-Right Solar offers for sale an optional activated carbon filter called “binchōtan”. It is a wood twig that has been pyrolized to convert it to activated carbon, a process with a long history in Japan. It is simply placed into your water crock or pitcher, and left there to sweep up any possible remaining organic volatiles in the distilled water. It should last much longer than the label suggests, because the distilled water is already practically free of any contaminants. Six binchōtan sticks are recommended for a carboy, two sticks for a pitcher, and one stick for a glass or water bottle.