10.) The coffee is stale. Coffee should be packaged using a 'gas-flush' method, where just prior to sealing, the bag, (or pillow-pack, or can), is flooded with nitrogen in order to displace the oxygen. (Packing and sealing within minutes of roasting also works fairly well, as at this stage the coffee is giving off lots of CO2, which displaces the oxygen, somewhat. And vacuum packing for cans works well too.) The p [...]
