Why Is It Important to Measure Food’s Internal Temperature?

Meat or other food looking cooked on the outside does not mean harmful bacteria inside have been destroyed. Internal temperature measured with a food thermometer is a much more reliable indicator than visual inspection. Even a chicken piece that looks properly browned on the outside may pose a foodborne illness risk if its interior has not cooked enough.

Why is a visual check not enough? Meat color can vary depending on the marinade, cooking method, and the meat itself, so judging whether it is still pink can be misleading. Some chicken pieces may look slightly pink near the bone even when fully cooked; this does not always mean they are undercooked. The reverse is also true: browned meat may not have reached a safe internal temperature.

What internal temperatures should different foods reach? Poultry such as chicken and turkey should reach at least 74°C / 165°F internally. Ground and otherwise processed red meats, such as ground beef and burger patties, should reach 71°C / 160°F. Whole cuts of red meat should reach at least 63°C / 145°F and then rest for 3 minutes; depending on the desired doneness, they can go up to 71°C / 160°F. Fish is generally considered safe at 63°C / 145°F. These temperatures are clearly stated in food safety authorities' published guidance. Correct thermometer placement also matters: insert the probe into the thickest part of the meat without touching bone. A reading against the bone can be misleading because bone conducts heat differently. For a more reliable reading, measure near the end of cooking at a few different spots.

Internal temperature checks also apply when reheating leftovers. When reheating food stored in the refrigerator, bringing its internal temperature to at least 74°C / 165°F to address possible bacterial growth is recommended. This is especially important for foods conducive to bacterial growth, such as rice and meat dishes.

Digital instant-read thermometers provide faster, more precise readings than analog thermometers. Since they give a reading within seconds, they can keep meat from being away from the oven or grill for too long. This type of thermometer is considered a relatively inexpensive but highly effective kitchen investment for food safety.

A common mistake is using a thermometer only for large cuts of meat. Mixed, hand-shaped foods such as meatballs, burgers, and stuffed vegetables also carry an internal-temperature risk because bacteria from the outside can spread throughout the meat during mixing. Do not skip thermometer checks for small shaped foods. Thermometers can lose calibration over time. A simple accuracy check is to place a thermometer in a glass of ice water and see whether it reads 0°C / 32°F. Repeating this check every few months can help maintain reliable readings over time and reduce the risk that the thermometer reads lower than the actual temperature.