title_body: Aluminium v's Ceramic storage
upvoted_answer: Typically aluminum packaging is actually a three (or more) layered packaging with aluminum not being in direct contact with the beans.  Aluminum is a superb barrier to air, and it is typically used as an internal layer to prevent air transferring into the bag, without being in direct contact with the beans.
  
  Keys to optimal packaging:
  
  Prevent light from reaching beans.  Light will help to speed oxidation of coffee oils.
  
  Prevent air from reaching beans but don't restrict air from escaping beans!  This is where the 1 way degassing valve comes in.  Coffee will offgas carbon dioxide if it is fresh.  High CO2 levels contribute to oxidation, so you want the ability for that gas to escape without constantly recirculating air in your container (which would also contribute to oxidation).
  
  I think ceramic or dark glass would both be excellent storage solutions provided they have a way to degas the coffee.  These materials (provided they have good methods of sealing the container) would prevent air transfer into the coffee, and would sufficiently block light to prevent oxidation.
  
  An example of an aluminum coffee bag I snagged from the internet has a PET internal liner, Aluminum barrier layer, and an LDPE external layer. So.. basically aluminum sandwiched between foodsafe plastic and something that looks good on a shelf =p