title_body: Drinking from a pewter mug?
upvoted_answer: To be honest, I think drinking carbonated (with CO2 at least) beer from pewter is asking for trouble if you do it regularly.  The tang you feel is dissolved metal and a component of that, depending on the pewter, may be lead (or could be copper, tin, bismuth, antimony, etc).  A major factor in that is acidity, and both hops and carbonation contribute.
  
  Acidic solutions react with metals to produce hydrogen gas and dissolved metal salts.  So carbonic acid from carbonated beer will react with the tin to produce hydrogen and tin carbonate, and the same basic process with other metals.  The specific metal that reacts will depend on the pewter.
  
  There are some ways around this.  You could, for example, coat the inside of the vessel with bees wax.  This can then be washed by hand with hot tap water and soap (and is a common method in making drinking horns).  This has the pro/con (depending on your taste) of imparting a slight honey taste to everything you drink out of the vessel.