Freezing greatly extends the storage life of meat and other foods because it halts all biological processes. Life requires liquid water, and freezing immobilizes the food’s liquid water in solid crystals of ice. Well-frozen meat will keep for millennia, as has been demonstrated by the discovery of mammoth flesh frozen 15,000 years ago in the ice of northern Siberia. It’s best to keep meat as cold as possible. The usual recommendation for home freezers is 0°F/–18°C (many operate at 10–15°F/–12 to –9°C).