To superchill food is to cool it to between –1°C and –4°C — just below the freezing point of water but above the point where the food freezes solid. At these temperatures a proportion of the water in the food turns to ice while the rest stays liquid, which slows microbial growth and enzymatic activity far more effectively than ordinary chilling at 0°C to 4°C. Superchilling extends the shelf life of fresh fish, meat, and poultry significantly without the texture damage that full freezing and thawing can cause, since the ice crystals remain small. It demands precise temperature control throughout the cold chain: drift a degree too warm and the benefit is lost, a degree too cold and the product freezes.