If I freeze food can no bacteria affect it?

No. Freezing preserves food by stalling the reproduction and growth of bacteria and other micro-organisms. Most disease-causing bacteria have evolved to thrive at temperatures close to that of the human body. The average household freezer maintains a frosty -18 degrees Celsius (0 degrees Fahrenheit) or below: in these conditions there is no liquid water available and the enzymes bacteria rely on cannot function.

Freezing therefore protects food from decay until you’re ready to use it. As water inside bacteria expands to form ice crystals it kills some of the micro organisms, though most are tough enough to survive the ordeal. They simply remain dormant, springing back into action when you take your dinner out of the freezer. You can limit their reproduction by thawing your food in the fridge or microwave rather than leaving it out at room temperature.

Answered by Alex Cheung.