The USDA‘s recommended safe minimum internal temperature of a hamburger when done is 160 degrees Fahrenheit. This is the recommendation for consumers cooking burgers at home.
The 2017 FDA Food Code (it’s updated every four years) states that a hamburger’s safe minimum internal temperature when done is 158 degrees Fahrenheit.
The FDA’s food code also updated in its recommendations a minimum internal temperature for ground beef of 155 degrees with a minimum 17-second holding time above that temperature.
So, why the discrepancies, and what’s the temperature for a cooked hamburger then? I will discuss the discrepancies in a bit, but let’s examine how to cook a safe and delicious hamburger first.
There are cooking and preparation methods that will allow you to cook and serve your hamburgers safely below 160 degrees Fahrenheit.
One cooking method that will allow you to safely serve a hamburger even at 140 degrees Fahrenheit is the cook and hold technique that will eliminate harmful bacteria through the process known as meat pasteurization.
I will also examine the preparation method of grinding your own meat that some culinary enthusiasts will proclaim makes consuming a medium-rare burger safe to eat.
Then I’ll show you the necessary steps that they skip before grinding that you need to take to limit the bacteria in a medium-rare burger.
In this article, I will detail these two methods and show you how to cook and serve a safe and delicious hamburger below 160 degrees Fahrenheit.
First, let’s look at the FDA’s holding time recommendation and how that can help us cook a burger that’s safer and juicer at the same time.
Time and Temperature: Pasteurization in Ground Beef Patties
The holding time stipulation of 17-seconds mentioned in the FDA’s recommended minimum safe internal temperature of 155 degrees Fahrenheit for ground beef is the key to cooking your burgers below 160 degrees Fahrenheit.
Destroying harmful pathogens in meat is not only achieved by higher temperatures but both temperature and time working together.
This process is known as meat pasteurization and it will allow you to cook your hamburger below 160 degrees Fahrenheit. Do you need special equipment?
Nope. Just cook your hamburger to one of the internal temperatures listed in the FDA’s Time and Temperature chart below and then hold it at or above that temperature for a specified amount of time and you will kill the same amount of pathogens as if you cooked it to 160 degrees Fahrenheit.
As you can see, due to practicality and time constraints, using this pasteurization technique for cooking hamburgers only makes sense above 140 degrees Fahrenheit. How do you do this? Read on.
Why 160 Degrees Fahrenheit is the Minimum Safe Temperature for a Hamburger When Done
Why is 160 degrees Fahrenheit considered the safe serving temperature for a hamburger?
160 degrees Fahrenheit is the temperature at which harmful bacteria such as E. coli and Salmonella are eradicated instantly from ground beef.
This conservative recommendation for the home cook is intended to safeguard against a “worst-case” scenario.
The FDA food code chart mentioned previously is based on a 6.5 log-10 reduction (or 6.5D reduction) in harmful pathogens such as E. coli and Salmonella.
What does that mean exactly?
In the context of killing bacteria in food, a log reduction is a measure of how thoroughly the cooking process reduces the concentration of harmful pathogens.
The log part of it refers to a logarithm. In this case, it is the ratio of levels of bacteria before and after the cooking process. An increment of 1 corresponds to a reduction in bacteria by a factor of 10.
A log reduction of 0 refers to no reduction in bacteria and a 1-log reduction corresponds to a 90% reduction.
Each log reduction increases the number of bacteria killed by a factor of 10:
- 1 log reduction = 90% reduction in Salmonella
- 2 log reduction = 99% reduction
- 3 log reduction = 99.9% reduction
- 4 log reduction = 99.99% reduction
- 5 log reduction = 99.999% reduction
- 6 log reduction = 99.9999% reduction
As you can see, a 6.5 log-10 reduction equates to an over 99.9999% reduction in bacteria. If you’re interested in learning more about the thermal destruction of microorganisms, here’s another link to the FDA’s literature.
Why Is the Minimum Safe Temperature of a Hamburger Higher Than a Steak’s?
Why is the minimum safe temperature of a hamburger higher than whole pieces of beef, like a flank steak for instance?
It is because harmful bacteria can exist on the surface of a piece of beef before it is ground.
When this beef is ground, this surface bacteria is then introduced and integrated all over the ground beef mixture.
So instead of having to worry about just killing the surface bacteria as you would cooking a steak, you now have to ensure that every part of your hamburger is free from harmful pathogens.
When you cook a steak on a hot surface the surface bacteria is immediately killed.
Is Ground Beef Done at 158 Degrees or 160 Degrees Fahrenheit?
So, why does there seem to be a discrepancy between some of the minimum safe temperatures recommended by the USDA, FDA, and the CDC?
Here’s a direct quote from the CDC (Centers for Disease Control and Prevention) pertaining to the guidelines for cooking ground beef:
The FDA Food Code says that restaurants should cook ground beef to 155°F for 17 seconds. But CDC and USDA say that consumers should cook ground beef to 160°F. The guidance for consumers is different because it is simpler to meet one standard (temperature) than two (temperature and time). Cooking ground beef to 160°F kills E. coli germs rapidly.
How about some intra-agency cooperation?
It appears that the difference in temperatures stems from the government agencies not wanting to confuse the consumers at home with too much information.
To simplify it, they’ve kept the recommendation for ground beef at 160 degrees Fahrenheit.
Even the FDA states two separate temperatures, as evidenced by this FDA temperature chart recommending 160 degrees Fahrenheit as ground beef’s safe minimum internal temperature.
This is different from the 158 degrees Fahrenheit recommendation that they published in the 2017 food code the very same year as that temperature chart.
For our purposes in this article, this discrepancy doesn’t come into play as we are going to cook and hold our hamburger to a lower temperature anyway.
Cooking a Hamburger to a Serving Temperature Below 160 Degrees Fahrenheit
How do you use the cook-and-hold method to cook safe and juicy hamburgers below the recommended minimum safe temperatures?
I’ll show you right now.
We are going to cook our hamburgers to an internal temperature of 140 degrees and then hold them above that temperature for 12 minutes.
Keep in mind I’m using a 5-ounce hamburger patty in this example. The cooking time will vary for you depending on the size of your meat.
First, preheat your oven to 250 degrees Fahrenheit. If you’re using a grill, don’t worry, you can move your burgers off to the side of the heat.
Form your hamburger patties to your desired size. Remember to make a 1/4 inch dimple in the middle of your hamburger patty. The outside of a burger cooks faster than the middle.
Meat shrinks as it cooks, the shrinking meat on the outside then pushes the uncooked meat in the middle up and out.
That’s why you get softball-shaped burgers if you don’t dimple them first.
Next, heat a skillet or your grill to medium-high heat for around 5 to 10 minutes. This will generally measure a surface temperature between 450 and 500 degrees Fahrenheit in your skillet or on your grill grates.
Grill your burger dimple side up for 3 minutes, then flip.
Grill the other side for another three minutes.
At the six-minute mark, your hamburger’s internal temperature will measure around 95 to 100-degrees Fahrenheit. To ensure that you don’t overcook one side you will need to flip it over every minute until you get close to 140 degrees Fahrenheit.
Once your hamburger reaches 140 degrees Fahrenheit internally, transfer it, still in the skillet, to the preheated oven.
Or if you’re grilling, just wrap your burgers in foil and move them to the side of the grill away from the heat.
Turn your oven off. Set a timer for 12 minutes. Your burger will invariably go up in temperature due to carryover cooking.
Grinding Your Own Meat for Hamburgers, Is it Safer?
Some people like their hamburgers cooked to less than 140 degrees Fahrenheit. It is at this point that some people suggest grinding your own meat at home.
What does grinding your own meat have to do with the minimum safe temperature for hamburgers?
The safety premise behind grinding your own meat at home presupposes that the piece of meat you’re grinding is free from bacteria on its surface.
You would then be able to grind this piece of meat and have no surface bacteria in your grind mixture.
Then you could cook your hamburger to temperatures usually reserved for whole cuts of beef, like a medium-rare steak for instance, generally in the 125 to 130 degree Fahrenheit range.
There are a few things that are logically flawed with this approach.
In fact, the USDA cautions against grinding beef at home.
On the USDA’s website, in the section about ground beef and food safety they state:
In a USDA-inspected plant, trimmed beef destined for grinding is tested for the presence of E. coli. However, primal cuts, such as steaks and roasts, are usually not tested. When stores or consumers grind these primal cuts, it’s possible that pathogens may be present on the raw beef, and neither you nor meat market employees can see, smell, or taste dangerous bacteria.
There is no way for you to know if the chuck roast that you’re grinding into hamburger is free from pathogens on the outer surface.
That is unless you decide to kill any surface bacteria by giving your meat a dunk in boiling water first before grinding, I’ll go into more detail on this in a minute.
Grinding Your Own Meat for a Hamburger
The process of grinding your own meat at home is touted as a safer way to consume undercooked ground beef at home.
This premise is based on the assurance that the whole piece of beef you’re grinding is free from any bacteria on its outside surface.
There is no way to know this, so you must take another step to ensure that the outside of your whole piece of beef is free from pathogens.
One way to accomplish this is to immerse your meat in boiling water or to sear the outside briefly.
I decided to immerse pieces of chuck roast in boiling water for 10 seconds. After their dip in the boiling water, I immediately dropped them in an ice-water bath to stop the outside from overcooking.
The ten-second boiling water plunge resulted in the pieces of chuck roast that had a surface temperature of 155 to 156 degrees Fahrenheit when measured with the Thermoworks IRK-2 Infrared Thermometer.
Considering that the surface of the chuck roast pieces were still measuring this temperature out of the water a second or two later, I don’t feel that it is a reach to assume the surface reached a higher temperature while in the water bath.
Am I willing to state that those pieces of chuck roast are totally bacteria-free? No, that would be irresponsible.
However, I am very confident that those pieces of chuck roast destined for the meat grinder have inherently less risk of bacteria because of the additional boiling water plunge.
This pre-treatment of meat pieces in boiling water is an abbreviated version of what Harold McGee recommends in his seminal work, On Food and Cooking: The Science and Lore of the Kitchen.
McGee is renowned the world over for his contributions to food science.
Can Freezing Kill Bacteria in Ground Beef?
No. The simple act of freezing your ground beef does not kill the possible bacteria that could be present. Freezing food to 0° Celsius or 32° Fahrenheit will only inactivate any bacteria that is present in your food.
Once your frozen food is thawed, the bacteria become active again and can multiply rapidly in the Danger Zone between 40 degrees and 140 degrees Fahrenheit.
Cooking a hamburger that is both flavorful and safe involves a certain level of risk mitigation.
My main goal in this article is to equip you with all of the necessary literature and information on limiting the risk potential associated with eating hamburgers below 160 degrees Fahrenheit.
Armed with that information, you can then make an informed decision on how to go about cooking and serving burgers that are safe for your family.
How you like your hamburger prepared is a personal preference. Some people like their hamburgers well-done, some like them medium-rare.
However, due to the bacterial issues associated with ground meat, preparing and serving a safe burger at temperatures generally reserved for whole pieces of meat such as steak is a challenging task for even the most experienced cook.
By employing cooking techniques such as the cook-and-hold method, you can serve a hamburger that is not only flavorful and juicy, but safe as well.
By bringing the internal temperature of a hamburger to 140 degrees Fahrenheit and holding it above that temperature for 12 minutes, you will kill the same amount of pathogens as you would at 160 degrees Fahrenheit.
People that want an even lower internal temperature for their hamburger will need to look at grinding their own meat after it’s been sterilized on the outside by either searing or boiling-water submersion.
Without that necessary step, you are putting a lot of faith in the chain of events that led that piece of beef to your kitchen.
Whichever technique you choose to prepare your burgers, always keep safety in mind. Oh, and a dependable meat thermometer.
Enjoy those burgers!