We try to explain the benefits of using copper in the vapor stream of a pot still. Stainless steel and copper are both acceptable but there is some data that supports the use of copper in order to remove sulfites in a spirit. Most sulfite production happens in fruitier washes as opposed to sugar or grain but nonetheless it is still a problem for some people. There are also people who will support the use of stainless steel exclusively for distilling. In the end it is up to the distiller. We have used both methods and are comfortable with either as opposed to selecting one over the other.