What to Freeze

• Freezer temperature largely depends on what foods you are freezing. Technically, any temperature below 32 F is considered freezing but many foods freeze and stay frozen at 20 F.
  
  Foods that are higher in sugar content like ice cream need to be stored at a temperature between 5 F and 10 F, while other foods like olive oil, for instance, have a much lower freezing point and thus need a temperature well outside the range of most commercial freezers to stay frozen.
  
  The first step in determining the highest possible freezer temperature is to consider the foods you will be storing in a freezer and the temperatures they will stay frozen.
  
  

Highest

• When you know what you are freezing you can consider the highest possible temperature to keep your freezer, below 32 F at the very least. Foods with high water content can be kept in a freezer that stays just below 32 F but other foods need a much lower freezing temperature. Keeping foods in the freezer that have not reached their own freezing point creates the perfect breeding ground for bacteria and spoilage, so carefully select what you will be keeping in the freezer.
  
  

Lowest

• Most commercially available freezers range down to about 5 F, while restaurant-style walk-in freezers can reach temperatures well below 0 F. It may be tempting to keep the freezer at a substantially low temperature but this can very easily lead to freezer burn, oxidation or other issues that can render the food unusable. Even if a food does not suffer from freezer burn, keeping it too deeply frozen can result in an unpleasant texture when thawed. Again, this is highly dependent on what foods you are freezing.
  
  

Ideal

• To provide a suitable margin for error, manufacturers recommend a freezer temperature of 0 F. For most popular foods this will allow for a low enough temperature to keep foods frozen while not dipping too low to risk freezer burn and not staying too high for bacteria and spoilage. Buy a thermometer and hang it in your freezer to monitor the actual air temperature and to safeguard against any malfunction of the freezer's temperature regulation components.