County Agent: Safe Microwave Cooking

By Candace Tucker, Family & Consumer Sciences Agent, UGA Extension Coweta County

Microwave ovens can be a useful appliance for you and your family. However, microwaves can cook unevenly and leave cold spots where bacteria can survive. Precautions must be taken to keep your food safe.

Below are tips to safely use your microwave oven to prevent foodborne illness.

Cooking in the Microwave

• Food items should be arranged evenly in a covered dish with some liquid added if needed. Cover the dish with plastic wrap or lid. Then, loosen the plastic wrap or vent the lid to let steam escape. The steam helps to kill harmful bacteria and ensure uniform cooking. Using cooking bags are another way to ensure safe, even heating.
• When cooking large cuts of meat in the microwave, be sure not to cook them on high power (100%). Cooking large cuts of meat on medium power (50%) for a longer period allows the meat to cook all the way through without overcooking the outside. If you have your oven user manual, follow directions in it.
• Stir dishes halfway through microwaving time or more often to eliminate cold spots and ensure more even heating.
• When partially cooking food in the microwave that will be cooked the rest of the way on the grill or in a conventional oven, be sure to move the food from the microwave to the other heat source immediately. Never partially cook food in the microwave and store it for later use.
• Always allow standing time before checking the internal temperature of the food. Standing time completes the cooking process of microwave cooked food.
• Use a food thermometer to make sure that food that has been cooked in the microwave has reached a safe internal temperature before serving. The thermometer should always be placed in the thickest area of meat or poultry, not near fat or bone. In whole poultry, the thermometer should be placed in the innermost part of the thigh. Cooking times may differ in microwaves due to varying power and efficiency. Cook foods to the following safe minimum internal temperatures, as measured with a food thermometer:

• Cook all raw beef, pork, lamb and veal steaks, chops, and roasts to a minimum internal temperature of 145° F before removing meat from the heat source. For safety and quality, allow the meat to rest for at least three minutes before carving or consuming. For reasons of personal preference, consumers may choose to cook meat to higher temperatures.
• Cook all raw ground beef, pork, lamb, and veal to an internal temperature of 160° F.
• Cook all poultry to a safe minimum internal temperature of 165° F in all parts.
• Microwaving stuffed, whole poultry is not recommended. The stuffing might not reach the temperature needed to destroy harmful bacteria. Cook stuffing separately to 165° F.
• Cook egg dishes and casseroles to 160° F.
• Reheat leftovers to 165° F.
• Fish is done when it reaches 145° F and flakes with a fork.

Defrosting in the Microwave

• When defrosting food in the microwave, remove the food from its packaging. Foam trays and plastic wraps are not heat stable and could break down during cooking, causing harmful chemicals to leach into the food.
• Immediately cook meat, poultry, egg casseroles and fish that have been defrosted in a microwave oven. Parts of the frozen food may have begun to cook during the defrosting process and partially cooked food should never be held for later use. Other heat sources such as an oven, grill or stovetop can be used to complete the cooking process.

Reheating in the Microwave

• When reheating foods in the microwave, cover them with a lid or microwave-safe plastic wrap. Covering helps to hold in moisture and provides safe, even heating.
• Allow for standing time for foods that have been reheated in the microwave oven. After the food has been allowed to stand, use a clean food thermometer to check that the leftovers have been heated to 165° F. before serving.

Containers and Wraps

• Only use cookware that is labeled safe for microwave use.
• Plastic containers such as margarine tubs, take-out containers and other one-time use containers should not be used in microwaves because of the risk of the container melting or warping and leaching dangerous chemicals into the food.
• Products that are safe to use in the microwave include microwave-safe plastic wraps, wax paper, cooking bags, parchment paper, and white microwave-safe paper towels. Plastic wraps should not touch foods during microwaving.
• Products that are NOT safe to use in the microwave include thin plastic storage bags, brown paper or grocery bags, newspapers or aluminum foil.

Adapted from E. Andress, UGA Cooperative Extension, April 2020.

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