I am having some issues when bottling using a beer gun. Beer poured out of the tap taste great, but beer bottled using a beer gun has a metallic taste. I have a container of star San that i put the nozzle of the gun after I fill 6 bottles and cap them. I clean the beer gun and run star San through the line prior to use. Bottles are sanitized using my dish washer on hi temp San rinse. No soap or jet dry is being used. I have no idea why I am getting the metallic taste.... Any help would be great!