How do I tell if raw meat has gone off?

Two different questions get answered with the same look and sniff: is this still nice, and is this still safe. Smell answers the first well. It answers the second only sometimes, because several of the organisms that make people ill produce no smell, no slime and no visible change at all.

Safety

Step by step

1. Check the date and the storage history first.Use-by is a safety date on raw meat, not a quality suggestion. If it has passed, or the meat has been out of the fridge for more than a couple of hours, or it thawed on the counter overnight, the sensory tests do not get a vote.
2. Open the pack and let it breathe for ten minutes before judging the smell.Vacuum-packed and modified-atmosphere meat has a confined, slightly sour smell on opening that fades quickly in air. Judging in the first thirty seconds condemns a lot of perfectly good meat.
3. Smell for sour, sulphurous or ammonia notes.Fresh raw meat smells faintly of not very much, or slightly metallic. Spoiling meat smells sour like off milk, or of eggs and drains, or sharply of ammonia. Any of those persisting after airing means discard.
4. Touch the surface.Fresh raw meat is moist but clean-feeling. A tacky, sticky or slimy film that leaves a residue on your fingers is bacterial growth on the surface and is the most reliable single sign there is. Wash your hands immediately afterwards.
5. Ignore colour, and check the exceptions.Brown beef and grey mince centres are oxygen chemistry, not spoilage. What does matter is a distinctly greenish or iridescent-green cast on raw meat, or grey-green patches on chicken, both of which mean discard.
6. Apply a tighter standard to mince, offal and poultry.Mincing multiplies the surface area enormously, so mince spoils fastest of anything on the counter and should be used within a day or two of purchase. Liver and kidneys are similar. Chicken gives less warning than beef and should be judged strictly.
7. When it is a close call, throw it out.The value of a pack of meat is trivial against food poisoning, and the people most at risk — anyone pregnant, elderly, very young, or with a weakened immune system — are usually the ones being cooked for.

Tips

• A dry, slightly darkened surface on beef that has sat uncovered in the fridge is dehydration, not spoilage. Trim it if it bothers you.
• Freezing at the use-by date stops the clock. If you know you will not cook it in time, freeze it that day rather than hoping.
• Meat kept in the coldest part of the fridge, on the bottom shelf, in a sealed container, lasts noticeably longer than meat in the door or near the top.

Common mistakes

• Cooking doubtful meat thoroughly and assuming that fixes it — Heat kills bacteria but several produce heat-stable toxins that survive cooking entirely. Thorough cooking is not a rescue for meat that has spoiled or been left warm.
• Washing raw meat to freshen it up — It does nothing to the bacteria and it sprays them around the sink and worktop. Pat it dry with kitchen paper instead, and bin the paper.

Questions people ask