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When cooking a meal, it’s always best to try and cook enough for just that meal. Improper handling over leftover foods can cause foodborne illness. To reduce the risk of foodborne illness from leftovers, here are some basic food safety tips.

A container of food in a fridge marked "leftovers".

Proper Reheating Method

Throughout the process of cooking, cooling, and reheating, food passes through the Temperature Danger Zone three times. This gives the disease-causing bacteria that may be in your food chance to grow and possibly reach unsafe levels which may make you sick. Therefore, it’s recommended that food is only reheated once to reduce the risk in using leftovers.

Bring reheated food to 74°C (165°F) or higher and hold this temperature for at least 15 seconds. Use a probe thermometer to check if the correct internal cooking temperature of the food is reached. Your food should reach the reheating temperature within two hours (this is to make sure that possible bacteria are not allowed to grow in the Temperature Danger Zone for too long).

Reheating Tips

  • Portion your leftovers and only reheat what you plan to use right away.
  • Smaller portions will reheat faster (remember, your food must reheat in less than 2 hours).
  • Microwaves heat unevenly so use a probe thermometer to make sure all areas of your food are reheated to the correct temperature.
  • Stir liquids to make sure all areas of the food heat evenly.
  • Hot food must be held at 60°C (140°F) or higher including reheated food.
  • Never use hot holding units to reheat food. These units are used to keep hot foods hot and are unable to reach high enough temperatures to reheat foods correctly. Reheat your foods first and then place it in the unit to keep hot.
  • Throw out any unused, reheated leftovers.


  • BC Centre for Disease. (2009). Ensuring food safety: Writing your own food safety plan – the HACCP way. A guide for food service operators. Food Protection Services. Retrieved from http:// www
  • Health Canada. (2010). Food safety tips for microwave ovens. Retrieved from http:// www micro-eng.php
  • National Food Service Management Institute. (2009). Food safety fact sheet: Reheating foods. The University of Mississippi. Retrieved from http:// nfsmiweb01

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