Some people make beer that has this character. Star Anise and Fennel are usually used to give this flavor. If that is not what you are after, it could be an infection of some kind. I would start by looking into cleaning/sterilization processes. Are you sure it is not a Chemical taste. I have seen Idaphor (I don't use any more) leave a chemical taste if it was not rinsed out thoroughly. Check the process all the way through from beginning to end, including cleaning anything that touches the Wort or beer: Bottles, kettles, spoons, etc.
Cheers
Preston