Woody, papery, cardboard-like flavours are age. The question is which kind.
Stale roasted coffee
The commonest cause. Oxidation strips the aromatics and leaves a flat, dry, cardboard character.
Timeline: noticeable at four to six weeks after roast in a sealed bag, faster once opened, and within days if the coffee is pre-ground.
Check the roast date. If there is only a best-before, assume this is the answer.
Old green coffee — “past crop”
Green coffee also ages, over one to two years, and develops a distinctly woody, baggy character that roasting does not fix.
This is why harvest year appears on good bags. Coffee sold cheaply late in the year is often past crop.
The difference
Stale roasted is papery and flat. Past crop is woody and dull, with a faint hessian-sack quality, and it is present even in a freshly roasted bag.
If the coffee was roasted last week and still tastes woody, it is past crop.
The other suspects
A dirty grinder with rancid oils in it. Clean it and re-taste.
Old paper filters stored near anything aromatic. Rinse them.
Baked roasting — a roast that stalled and dragged — tastes flat and papery from day one. That is the roaster’s fault, not yours.
Last reviewed 8 August 2026