title_body: How can I identify whether coffee is expired or not?
upvoted_answer: Roasted coffee beans behave differently during storage than raw ones. Heat treatment not only changes the color, smell, taste and even the size of the coffee beans, but also reveals the coffee – a bouquet of aromatic oils that evaporate very quickly. The shelf life of roasted coffee varies greatly depending on the storage conditions.
  
  Processed grains, which are stored in a conventional, leaky container-jar or box – have a shelf life of 10-14 days.
  Packaging in household conditions using foil will extend the shelf life up to 3-4 weeks.
  Fried grains Packed in sealed four-layer paper bags can be stored for up to 6 months. If the packages have an additional polymer coating inside, the period increases to 9 months.
  Roasted coffee beans can be stored for up to 12 months in heat-sealable film or foil-based packages. Such packages have a special gas discharge valve. It is required for freshly roasted coffee beans, after roasting, they continue to release carbon dioxide, thanks to the discovery of the smallest internal capsules. If you let the beans completely exhale, then they will be subjected to strong oxidation.Fried grains in opaque jars with hermetically lapped lids, Packed in a factory way, also have a long shelf life-up to 18 months.