The ideal freezer temperature is 0 Fahrenheit (-18 Celsius) for storing food. And -10 Fahrenheit (-23 Celsius) is recommended when freezing food. The faster food freezes the smaller the ice crystals.The smaller the ice crystals the smaller the change in texture and better quality when thawed.f you want to test your freezer to see what temperature it is use a freezer thermometer. Ideally read the thermometer after the freezer door has been closed for quite awhile, like first thing in the morning, so you get an accurate reading.