A Planet Cheese reader asked me recently about ammoniated cheese. What causes that unwelcome smell and can anything be done about it? I call it the death rattle because it’s usually a sign that the cheese is not long for this world. Most cheeses give us clues when they’re flawed or heading south; learning to recognize those sensory signals can avert a purchase you may regret. So in this journey to the dark side, let’s take a look at some not-so-nice cheeses and analyze what may have gone wrong.