What Temperature Kills Food Bacteria? Cooking, Holding & Reheating Charts

Cooking food isn’t just about making it taste good – it’s also our frontline defense against harmful bacteria. But how hot is hot enough to ensure our food is safe? We’ve all heard things like “cook chicken until the juices run clear” or “make sure your leftovers are piping hot,” but it helps to know the specific temperatures that knock out those pesky germs. In this article, we will explain what temperatures kill food bacteria and provide practical temperature guidelines for cooking, hot holding, and reheating food safely. Essentially, we’re creating a cheat sheet (or mini “charts” in words) for you to know the key numbers that matter in the kitchen.

Imagine grilling a burger – on the outside it looks done, but inside it might still be undercooked. If it’s not hot enough in the middle, bacteria like E. coli could survive. Using a thermometer takes the guesswork out. Similarly, if you’re keeping a buffet warm or storing leftovers, certain temperature targets ensure bacteria aren’t growing or surviving. Let’s break it down into three parts: Cooking temperatures, Holding temperatures, and Reheating temperatures – with the critical numbers you should remember.

Cooking Temperatures to Kill Bacteria

When we cook food, we’re aiming to reach a temperature that is lethal to bacteria (and viruses or parasites that might be present). Different foods have different recommended safe cooking temps, mainly because of the types of bacteria likely to be in them and the texture of the food.

Here are some key safe cooking temperatures (internal temperatures) for common foods, as recommended by food safety authorities:

• Poultry (chicken, turkey, duck) – 165°F (74°C). This applies to whole birds, poultry pieces, and ground poultry. Poultry is often contaminated with Salmonella or Campylobacter, which are effectively killed at 165°F. This temperature also provides a margin to ensure even the innermost parts (like stuffing in a turkey, or the center of a chicken breast) are safe. In practice: Cook chicken until it reaches 165°F at the thickest part. For whole birds, test in the thigh and breast. The meat may be white or slightly pinkish near the bone; temperature is the true indicator. At 165°F, you’ve destroyed the harmful bacteria.
• Ground meats (beef, pork, lamb, veal) – 160°F (71°C). Ground meat is more prone to having bacteria throughout (since grinding mixes any surface bacteria into the middle). E. coli O157:H7 in ground beef, for instance, is a big concern – 160°F ensures they’re killed. In practice: Cook hamburgers until the center is 160°F. That usually means no pink in the middle, although color isn’t a foolproof sign. Using a thermometer is best, since some patties can brown before reaching 160°F. Sausages (if fresh, not pre-cooked) also should hit 160°F unless otherwise specified.
• Steaks, roasts, and chops (beef, pork, lamb, veal – intact cuts) – 145°F (63°C) + a 3-minute rest. Intact muscle meats can be cooked a bit less because bacteria primarily live on the surface of an intact piece. When you sear the outside, you kill those surface bacteria. The interior of a steak or roast is sterile in theory (unless it’s “mechanically tenderized” or injected, which changes things). So medium rare is okay for steak as long as it reaches 145°F at least briefly. The 3-minute rest means after taking it off the heat, let it sit – the internal temp stays at or goes above 145 for a few minutes, which continues to kill pathogens. In practice: Use a thermometer in the center of the thickest part. For example, a pork chop at 145°F will be a bit pink – that’s now considered safe and yields juicier meat than the older guideline of 160°F for pork (which was for Trichinosis, but that parasite is largely eradicated in commercial pork). Still, many people prefer cooking pork a bit more; it’s personal as long as 145°F is reached.
• Fish and shellfish – 145°F (63°C) (or “cook until opaque and flakes easily” for fish). Fish is generally safe at lower temps compared to meat, but 145°F is a good rule for killing parasites or bacteria. Many chefs cook fish to slightly lower for quality, but from a safety standpoint, 145°F ensures any potential worms or bacteria (like Vibrio in seafood) are killed. For shellfish like shrimp, crab, lobster – cook until they’re opaque/pearly and shells (for bivalves) have opened. For oysters, clams, mussels, cook until shells open; that indicates they’ve hit a safe temp inside.
• Eggs – Cook until the yolk and white are firm, or if making dishes like quiche or casserole containing eggs, aim for 160°F (71°C). Salmonella in eggs is typically inside the yolk, so a runny yolk is a risk unless the egg is pasteurized. For safety, sunny-side-up or soft eggs should be made with pasteurized eggs if you want them runny. Egg-based sauces or custards should reach 160°F. You’ll notice at ~160°F eggs thicken (custard coats a spoon) – that’s a good sign it’s done.
• Casseroles, stuffings, mixed dishes – 165°F (74°C). If you have a lasagna or a casserole with various ingredients (especially if it has eggs or meats), best practice is to go for 165°F throughout, since it’s essentially like leftovers recombined. Stuffing inside poultry should reach 165°F too (if you stuff a turkey, the center of the stuffing is the coolest part; many recommend cooking stuffing separately to ensure it can reach 165°F without overcooking the bird).
• Hot dogs, precooked ham (reheating) – While these are pre-cooked, if you want to be extra safe (especially for at-risk individuals), reheat hot dogs, deli meats, and fully cooked ham to 165°F as well. The USDA advises that for people at risk (pregnant, elderly) to avoid unheated deli meats or to steam them hot, because of Listeria risk. If you buy a precooked ham that says to reheat, heat it to at least 140°F (60°C) if it was packaged in a USDA-inspected plant, or 165°F if not sure.

How heat kills bacteria: Essentially, high temperatures cause bacterial proteins to denature and enzymes to stop functioning, leading to cell death. Most food pathogens are killed in seconds at 165°F. Even at 155°F, given a bit more time (like 30 seconds), many will die. Cooking recommendations build in a safety margin, taking into account factors like how uneven home cooking can be.

Using a thermometer: The only reliable way to know you’ve hit these temps is using a food thermometer. They are inexpensive and one of the best investments for kitchen safety. Insert into the thickest part of meat, avoiding bone (bone conducts heat differently). For thin items like a burger, insert from the side if needed.

Carryover cooking and resting: Some foods will continue to rise in temperature after removal from heat (carryover). Large roasts might go up another 5-10°F while resting. This is good for safety and quality. Resting meat also allows juices to redistribute. But for safety, the important part is that at some point the minimum temp was reached.

Safe Holding Temperatures (Hot Holding and Cold Holding)

Killing bacteria with cooking is one thing, but what about keeping food safe after it’s cooked? This is where holding temperatures come in, which is basically about keeping hot foods hot and cold foods cold so that any bacteria that might reintroduce or survive can’t grow.

• Hot holding: If you’re keeping food warm for serving (like on a buffet, in a slow cooker, or just waiting to serve dinner), keep it at 135°F to 140°F or above. Many guidelines say at least 135°F (57°C). Some use 140°F as a round number. This temperature is above the growth range for almost all bacteria, meaning they won’t multiply. It’s not quite hot enough to kill bacteria rapidly, but it prevents growth and slowly may kill some. For practical purposes, aim for around 140°F. Chafing dishes with Sterno, warming drawers, crockpots on “warm” – make sure these devices can hold food at that temp. Tip: If food has been cooked and held hot, check the temp every so often with a thermometer to ensure it’s not dropping into the 120s or lower. If it does, either reheat it back up to 165°F and then hold, or if that’s not possible, you should discard after the 2-hour mark.
• Cold holding: Cold foods should be kept at 40°F (4°C) or below. Your fridge should ideally be at 37°F or so to ensure food stays under 40. Buffets serving cold items often put the serving bowls on ice. This is to keep say, salads or seafood chilled while out. Above 40°F, especially into room temp, any bacteria present can start multiplying again. Think of cold holding like hitting the pause button on bacterial growth.
• Danger Zone reminder: Between about 40°F and 130-135°F is the risk zone for holding. Bacteria that survived cooking (like spores of C. perfringens or B. cereus) can wake up and multiply if food drops into that range for too long. That’s why you’ll see guidelines like “if hot food falls below 135°F for more than 2 hours, discard it”.
• Steam tables / warming ovens: If using these for say catering or potlucks, make sure to preheat them and add hot food (don’t put lukewarm food in and expect them to heat it up – they’re meant to hold, not cook). Cover foods to retain heat and moisture.
• Thermal carry containers: For transporting, like casseroles to a picnic, use insulated bags or coolers (hot foods in one, cold foods in another with ice packs). The idea is to keep foods out of the Danger Zone during transit too.

Proper Reheating Temperatures (for Leftovers or Previously Cooked Foods)

When it comes to leftovers or precooked dishes that need to be reheated, the goal is to heat them enough to kill off any bacteria that might have grown during storage (or were there to begin with). The standard is 165°F (74°C) for reheating.

• Leftovers: Always reheat leftovers to reach an internal temp of 165°F. This ensures that if any bacteria multiplied in the fridge (for example, say your fridge is a little warm or the food stayed in the 40s°F too long, or maybe some L. monocytogenes grew slowly), they’ll be killed. Also, spores from C. perfringens or Bacillus cereus that might have germinated during cooling will be destroyed. Soups should be brought to a rolling boil (212°F) which is overkill but an easy way to see it’s hot enough. For solid leftovers like a casserole, using a food thermometer is wise because microwaves can leave cool spots.
• Microwave reheating: If using a microwave, cover the food and rotate/stir it for even heating. Microwaves often heat unevenly. Always let microwaved food rest for a minute or two after cooking – during this time, the temperature can equalize and actually continue to rise in cooler parts. Then check the temp in a couple spots if possible. You want 165°F throughout. Use medium power for longer if you find the outside is lava hot and inside is cold.
• Sauces, soups, gravies: Bring them to a boil when reheating. That will definitely exceed 165°F. Stir while heating to avoid pockets of cooler temp.
• Reheat rapidly: Guidelines say when reheating foods (especially in food service), get it from fridge temp to 165°F quickly, within 2 hours max (and preferably faster). Don’t put something on a low burner for a long slow warm – that just gives bacteria time in the Danger Zone. Use proper heat.
• Never reheating more than once: It’s a good practice not to repeatedly cool and reheat the same food. Each cycle gives potential for contamination and growth. If you reheat a big pot of chili, and then cool it again, you’ve had two rounds of going through the Danger Zone. Better to reheat only what you need. If you did reheat a big batch, it’s best to discard leftovers that were reheated (or at least know you’re taking a slight risk if you cool them again).
• Special case – previously cooked, commercially packaged foods: If you have something like a fully cooked ham and it’s vacuum-sealed from a plant, you can reheat to 140°F for serving (as the USDA notes). But if it’s leftover ham or not in that category, go to 165°F. For things like leftover pizza or rice, 165°F is still a good target (it means “steaming hot”).

A Quick Temperature Reference Chart (for easy recall):

• 40°F (4°C) and below: Safe refrigeration temperature. Bacteria don’t grow or grow very slowly.
• 0°F (-18°C): Freezing. Virtually all bacteria dormant, some slowly die.
• 41-135°F (5-57°C): Danger Zone – bacteria grow rapidly here.
• ~70-120°F (21-49°C): Very fast growth zone (middle of Danger Zone).
• 135°F (57°C): Lower end of safe hot holding. Try to aim a bit higher (~140°F).
• 145°F (63°C): Safe for whole cuts of meat (with rest), fish; also general threshold where most pathogens start dying quickly.
• 160°F (71°C): Safe for ground meats and egg dishes.
• 165°F (74°C): Safe for poultry, leftovers, and anything you want thoroughly safe (kills almost everything instantly).
• 212°F (100°C): Boiling point of water. More than enough to kill bacteria; used in canning processes (with pressure to get even higher temp for botulism spores).

Remember, these temperatures assume you’re hitting the entire food product – surface and inside. Bacteria hide in the center of a burger or deep in a casserole, so that’s where you need to ensure the heat reaches.

Why charts and guidelines matter: They’re based on science – for example, Salmonella is killed in under a second at 165°F, but might take 60 seconds at 150°F. Rather than making people do calculus with time-temp combos, the agencies give simple-to-follow temps that incorporate a safety margin. Following these takes much of the risk out of the picture.

Conclusion:
Using a thermometer and knowing these key temperatures can make you a kitchen superhero when it comes to food safety. Cooking to the right temperature ensures you’ve wiped out dangerous bacteria. Keeping food hot (above 135°F) or cold (below 40°F) means you’re not giving any survivors a chance to regrow. And reheating leftovers properly means you get a second round of safe enjoyment from your meal. It might seem like a lot of numbers at first, but the critical ones – 40°F, 140°F, 160°F, 165°F – will soon become second nature. When in doubt, heat it out (and then maybe thermometer it, to be sure)! With these guidelines, you can confidently serve food that’s not just delicious, but also free of unwelcome microbial guests.

References (Cooking & Temperature):

1. CDC – Cook to the right temperature (Food Safety). (Recommends internal temperatures: 145°F + rest for whole cuts of beef, pork, lamb, veal; 145°F for fish; 160°F for ground meats and egg dishes; 165°F for all poultry, and for leftovers and casseroles.)
2. gov – Safe Minimum Internal Temperature Chart. (Lists safe cooking temps: e.g., 165°F for poultry, leftovers; 160°F for ground meat and egg dishes; 145°F + 3 min rest for whole meats; also notes to reheat precooked ham to 140°F if USDA-inspected, otherwise 165°F.)
3. California Dept of Education – Temperature Danger Zone/Holding. (Defines danger zone as 41°F to 135°F; advises holding cold foods at 41°F or below, hot foods at 135°F or above, and discarding food if held in the zone >4 hours.)
4. gov – Prevent C. perfringens (Keep hot food hot). (Advises keeping cooked food at 140°F or warmer if not serving immediately; never leave perishable food in the danger zone >2 hours, or >1 hour above 90°F; and refrigerate leftovers within 2 hours.)
5. Fairfax County PDF – Cooking and Reheating Temperatures. (States that leftover food items must be reheated to 165°F for 15 seconds within 2 hours; if it takes longer, it must be thrown away – highlighting safe reheating practice.)
6. CDC – Microwave and Reheating Guidance. (Emphasizes microwaving food thoroughly, including stirring and rotating, and checking that microwaved food reaches 165°F; also to let food stand for a few minutes after microwaving to allow even heating.)
7. FDA – Listeria and Deli Meat Safety. (Notes that ready-to-eat products like hot dogs or deli meats can be safely eaten if reheated until steaming hot, since Listeria is a concern in those; FSIS has zero tolerance for Listeria, and they recommend reheating these to kill any potential contamination.)
8. Healthline – Importance of Correct Reheating. (Explains that heating foods above 140°F causes bacteria to die off, hence proper cooking and reheating reduce food poisoning risk; references FSIS and others for safe cooking temperature info.)
9. Ohio State University Extension – Safe Minimum Internal Temp Chart (PDF). (Reiterates USDA safe temps: 165°F for poultry and leftovers, 160°F ground meats, 145°F whole meats + rest, etc., and the importance of a thermometer.)
10. CDC – Chill guidelines. (Keep fridge at 40°F or below, and refrigerate perishable foods within 2 hours (or 1 hour if above 90°F) – reinforcing the need to quickly chill to prevent growth of bacteria that were not killed or introduced after cooking.)