The Slowcook at Spydog Farm The Slowcook at Spydog Farm

When is Your Pork Roast “Done”?

January 3rd, 2011 · 25 Comments · Posted in Recipes

Does your pork roast look like this?

A friend invited us to dinner over the holidays in a jubilant mood: She’d scored a huge pork rib roast at Safeway at a ridiculously cheap price.

Okay, so it wasn’t a local, pastured pig. It probably came from a horrible factory farm. But we were invited to eat it, not give a critique. Plus my friend wanted help with the cooking. I loaned her our restaurant-style roasting pan with the non-stick rack insert and gave some basic instructions for cooking. She did a great job–stuffing the pork with garlic and rosemary–and it was a beautiful thing to behold in the oven, all mahogany brown and juicy.

But how would we know when it’s done? she asked. Her brother, a former professional chef, had recommended cooking this beast of a roast to 150 or 160 degrees (all temps will be given in Fahrenheit henceforth). She even had a new instant-read thermometer for me to use.

Hah! I replied. If we cooked the pork to that temperature, the roast was sure to be overdone and dry. I’d shoot for 135, I told her.

When I started probing with the thermometer, I found that the small part of the roast had already hit 150 degrees. At the other end, where the loin was at least twice as big in circumference, the temperature was more to my liking: 135. I called it done.

With a carving fork and a set of tongs I lifted the roast onto a wooden cutting board and let it rest 15 minutes with the thermometer in place. At the thickest end, the reading had only crept up to 140. I started carving there to see what it looked like inside. It was beautifully pink and oozing fatty juices.

My friend, looking on, grimaced and cleared her throat with obvious dismay. “Is there any way we can cook that more in case people want it more well done? I mean, trichinosis?”

I could not convince her that this end of the roast was perfectly cooked, exactly the way Alice Waters herself would have wanted it. My friend requested a slice  from the other end, where the temperature by now was reading closer to 160.

I loved my pink slice of pork roast and gladly chewed what meat was left off the bone. But it reminded me that I’ve wanted to write on this subject for a long time–meaning how the cooking world is still confused about when, exactly, pork is “done.” In fact, if you consult any number of cookbooks and recipe sources, you are likely to find them all over the map. Many are still following ancient advice from the U.S. Department of Agriculture that pork must be cooked to 160 degrees to remove any risk of trichinosis or other pathogens.

So I went to the USDA website to see exactly what they have to say.

“Humans may contract trichinosis (caused by the parasite, Trichinella spiralis) by eating undercooked pork. Much progress has been made in reducing trichinosis in grain-fed hogs and human cases have greatly declined since 1950,” reads the USDA’s pork advisory. “Some other food-borne micro-organisms that can be found in pork, as well as other meats and poultry, are Escherichia coli, Salmonella, Staphylococcus aureus and Listeria monocytogenes. They are all destroyed by proper handling and thorough cooking to an internal temperature of 160 °F.”

Indeed, trichinosis doesn’t sound like much fun at all. If the eggs get into your body and hatch, they quickly multiply into thousands of little worms. To find out how big a risk trichinosis is, I Googled my way over to the U.S. Centers for Disease Control and Prevention. Turns out, this previously rampant pig-borne disease is not such a big problem any more, largely because of a change in feeding methods.

“During 1997-2001, an average of 12 cases per year were reported,” says the CDC. “The number of cases has decreased because of legislation prohibiting the feeding of raw-meat garbage to hogs, commercial and home freezing of pork, and the public awareness of the danger of eating raw or undercooked pork products. Cases are less commonly associated with pork products and more often associated with eating raw or undercooked wild game meats.”

Intrigued, I shuffled over to my cookbook library and pulled out Harold McGee’s seminal work on kitchen science, the newly revised edition of On Food and Cooking. “Uncooked garbage,” McGee writes, “was banned as pork feed in 1980, and since then the incidence of trichinosis in the United States has declined to fewer than ten cases annually. Most of these are not from pork, but from such game meats as bear, boar, and walrus.”

I haven’t run across much bear and boar meat lately, and even less walrus. That’s a relief. Better still, writes McGee, not only have improved hog raising practices reduced the risk of trichinosis to almost zero,  it’s “now known that a temperature of 137, a medium doneness, is sufficient to kill the parasite in meat; aiming for 150 degrees gives reasonable safety margin.”

I began pulling cookbooks off the shelves to see what cooking temperatures other famous authors recommend.

Julia Child, in The Way to Cook, published in 1989, called for cooking a roast pork loin “to a thermometer reading of 160,” perfectly in line with the USDA. I wondered what Child’s nemesis, Madeleine Kaman, would have to say about that. But she concurred, writing in The New Making of a Cookas recently as 1997 that a pork loin “can be served at an internal temperature of 160 degrees Fahrenheit, as recommended by the UDSA.” The La Varenne Pratique, named for the culinary school, leans even more toward the conservative end, and hints that doneness might be measured with a tool other than a thermometer. A pork roast is done, declared author Ann Willan, when it is “tender when pierced with a two-pronged fork, at least 170 degrees.”

I expected The River Cottage Meat Cookbook, published in 2007 and considered by some the apex of meat cookery, to be somewhat more modern in its approach. But it still hues to the old line: 160 degrees for “medium,” and 170 for “well done.” And that’s when the meat is to be removed from the oven. “A rest of twenty to thirty minutes,”writes author Hugh Fearnley-Whittingstall, “will then complete the roasting, raising the temperature in the center of the meat by several degrees.”

Even Steven Raichlen, the master of the grill, in How to Grill calls for cooking a stuffed pork loin to 160 degrees.

So what’s wrong with cooking pork to 160, 170 degrees or more? I like the answer given by Bruce Aidells, the king of all things sausage and author of Bruce Aidells’s Complete Book of Pork.

“When meat cooks, the muscle fibers begin to shrink,” Aidells writes. “By the time the meat exceeds 140 degrees (medium-rare to medium), the fibers have begun contracting enough to squeeze moisture out of the cells…and once the meat reaches 160 degrees and higher, enough moisture has been squeezed out to make it downright tough and dry.”

Aidells isn’t worried about trichinosis. He says the parasite can be killed off either by cooking pork to 137 degrees, or by first freezing it for at least seven days at -10 degrees.The trend definitely has been in that direction among restaurant chefs. But some cookbook authors are still giving out dubious advice.

Alton Brown, the Food Network’s kitchen wiz, for instance, seems to be on the right track, then writes this boner in I’m Just Here for the Food: “A government internet site I checked out recently states that poultry must be cooked to a final internal temperature of 180 degrees F, while another site suggests that all fresh pork cuts be cooked to 170 degrees F. ,” Brown says. “Both seem pretty silly since salmonella dies instantly at 165 degrees (14 minutes at 140 degrees F. will do the job too), and trichinae (the parasites responsible for trichinosis) die at 170 degrees F.”

Or maybe that last part was a misprint. Pork, Brown declares, “should be cooked to 150 degrees F.”

The acclaimed chef Judy Rogers, in The Zuni Cafe Cookbook, seems to get it right when she says, “For a juicy roast that is cooked through, but with a faintly rosy cast,” roast to 135 degrees. (If the eye of your roast is smaller than 4 inches across, cook it to about 140 degrees; it will stop cooking more abruptly when you remove it from the oven.)” As Rogers explains, a pork roast “will continue to cook as it rests…” But she then goes loopy and asserts that “the temperature should climb to about 160 degrees. The meat will be cooked through but still moist.”

I think some chefs and cookbook authors just pretend to take actual measurements with their thermometers when they test these recipes. Assuming they actually test the recipes. Cooking, alas, is not a science, and very often is not treated as such by the so-called experts.

Rogers learned from Alice Waters at Chez Panisse. With the huge influence she wields on America’s cooking and dining habits, it’s instructive to see Waters’ own progression on the pork doneness issue. In the Chez Panisse Menu Cookbook in 1982, for instance, Waters wrote that a pork loin brined, then charcoal-grilled, “is done when the internal temperature is 137 degrees F. The meat will be pinkish because the brine affects its color, but is done and safe to eat at this temperature.”

Six years later, writing with another acolyte, Paul Bertolli, in Chez Panisse Cooking, Waters advised to roast pork in the oven “to an internal temperature of 140 degrees F.” But my jaw dropped when I read what Waters recommended in 1999, in the Chez Panisse Cafe Cookbook: Her roast pork loin with rosemary and fennel should be cooked only “until the internal temperature registers 130 F. on a meat thermometer…Remove the roast from the oven, cover loosely with foil, and let rest in a warm place for at least 15 minutes. This,” Waters explains, “allows the juices to stabilize and the roast to continue cooking slowly without drying out. The meat will be moist, with the barest tinge of pink.”

The good ‘ol Joy of Cooking, 1997 edition, concurs that a pork roast should have a “pale pink blush and lots of clear juice” when done. But it advises cooking a pork loin “until a meat thermometer inserted in the thickest part of the meat registers 155 to 160 degrees….”

I surfed the internet certain I would find some real whoppers at the more popular recipe sites. But Martha Stewart thumbs her nose at the USDA and recommends roasting pork loin only to 150 degrees. Rachel Ray surprised me by advising a finished temperature of 145. Good Housekeeping concurs with Ray–145 degrees–but Better Homes and Gardens is still leaning more in the federal government’s direction. It calls for 155 degrees, adding that the temperature of the meat after resting “should be 160 degrees.”

My favorite explanation of the pork roasting phenomenon, including the most current information on pathogens, cooking temperatures, and the tendency of roasts to “coast”–or continue cooking–after they are removed from the oven, remains the one offered in Bruce Aidells’s Complete Book of Pork.

But, with apologies to Mr. Aidells, I don’t think you need to rush out and buy it. You now have everything you need to know to serve the perfect roast pork–pink and juicy–without sending your guests to the hospital. Right?

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  • bob del Grosso

    Ed
    I think many cookbooks authors are told by the publisher’s legal department to parrot USDA temps to limit liability. I just heard a story along this line from someone who’s working on a butchery book that includes recipes for curing meat. Her publisher told her that all of the cured meat recipes must includes nitrite and or nitrate. They are worried that if someone gets sick after making a recipe without them, they will be sued.

  • Ed Bruske

    Indeed, Bob, I have run into some of that with magazines and newspapers. And there are lots of cookbooks that avoid the issue entirely–they never address the doneness question. But there obviously are exceptions. Do they prove or disprove the rule?

  • Nat West

    Ed, how about another of these posts for other meats, particularly roasted chicken? I pull out all my meats from the oven at about 140 degrees. As an example, I was deep frying a turkey for Thanksgiving and I couldn’t get the thickest part of the breast above 130 while in the oil. The skin was browning too much, so I removed it. After sitting for twenty minutes or so, I couldn’t get a reading under 160 anywhere!

  • Ed Bruske

    Nat, have you calibrated your thermometer lately?

  • Nat West

    Yes, I actually calibrated it a couple weeks ago, before the deep-fried turkey incident. I assumed the large jump had to do with a combination of mass (17 pound turkey) and hot oil, not just hot air.

  • Mrs. Q

    Great advice, though I may end up suing you later. Just saying…
    🙂

  • Linda Franklin

    Good research, and good info. For myself, I actually still love well -done falling-off the-bone pork: a shoulder roast that has lots of fat and won’t be dry… it’ll be tender and succulent, delicious. A pork loan roast, dry roasted to those USDA temperatures would be pretty poor eating. How lovely that we don’t feed our pigs raw garbage anymore. I am so glad it’s cooked. Actually feeding pigs “slop” is traditional farm food for pigs, but I am afraid of what the industrial farms use as their garbage. I’ll stay away from those vendors as much as possible.

  • Joanna Cary

    Hi Ed … very interesting post. I think I’d be inclined to overdo factory farmed pork because I’d trust it less for nasties (of all sorts).

    And, of course, if it’s a belly of pork, then it really doesn’t matter if you roast the hell out of it, because it will stay beautifully moist.

    But generally, good meat raised in a field somewhere near here, roasted until not quite done, then left to settle for half an hour before eating.

    thanks … lots to think about
    Joanna

  • Kevin

    Ed,
    I did a fair bit of research on killing micro-organisms a few years ago and indendently confirmed that trichinosis is killed at 137F. I never cook a pork loin past 145F and prefer about 143F. Note, it’s also worth noting that carry-over cooking only applies to relatively high-heat methods (325 and above). This is because the outer layers of meat build up excess heat that then must spread to the rest of the roast. If you use a low-heat method (250F) you get very little carryover cooking.

  • Ed Bruske

    Good point about the “carryover” cooking, Kevin. People should think of this in terms of what an ocean liner would do if you cut the power. The bigger the ship, and the faster it was going, the farther it will coast after the props stop turning.

  • Ed Bruske

    I received an e-mail from Steven Raichlen, one of the world’s foremost experts on grilling meat and author of numerous books on the subject. He gave me permission to publish it as a comment:

    Hi, Ed,

    Fascinating blog on cooking pork and it’s always nice to be mentioned. Thanks!

    I have a few additional thoughts for you on the pork doneness and temperature issue.

    1. Doneness has a psychological component as well as a chemical, thermal, and physical component. Pink pork may be safe to eat, but many people (including most of my students at BBQ U) would find it unappetizing.

    2. In a wide variety of barbecue cultures, people like their roast pork medium-well to well done. The short list includes Germany (where Spiessbraten is always served well-done), Greece (where kandosouvle comes off the rotisserie well-done), and Spain (where lechon and pinchos) are cooked well-done. All three dishes are pork masterpieces–I profile them in Planet Barbecue.

    3. Well-done doesn’t necessarily mean dry. Consider North Carolina’s pulled pork shoulder or the cochinita pibil of the Yucatan. Both are cooked to at least 190 degrees and both are as tender and succulent as any meat served rare or medium-rare. You need this high temperature to break down the muscle fibers enough so you can pull or chop the meat into the traditional shreds.

    For roast pork, I’m sticking with 160 degrees (155 if you allow for a little additional cooking after the meat comes off the grill). For pulled pork, jerk pork, or Spiessbraten, 190 to 195 degrees.

    Cheers!

    Steven Raichlen

  • otropogo

    A year or so ago I asked an expert at the British Columbia (Canada) Centre for Disease Control whether he could direct me to a lab which could inspect wild boar or bear meat for trichinae. He said he knew of no such lab in all of Canada, and that, were I able to find one, the inspection would probably prove prohibitively expensive. His explanation was that the “Canadian Pork Herd” had been decreed “trichinosis-free”, and therefore inspection of carcasses for this pathogen had long been discontinued nationally.

    This situation worries me considerably, as I’m partial to smoked venision sausage, especially Landjaeger, which my butcher assures me, requires the addition of 25% pork, due to the venison’s leanness. And I have serious doubt about the “trichinosis-free” condition of the Canadian “herd”, since pigs are known to be extremely resourceful, intelligent, and omnivorous, and thrichinosis can be acquired simply by ingesting the meat of a carrion bird, such as a Raven, or a carnivore, such as a coyote.

    I see three glaring gaps in the article above, informative as it is:

    First, there is no mention of smoked pork, widely considered a great delicacy. Secondly, there is only a single mention of the previously much-touted strategy of freezing trichenae to death. And finally, there is no suggestion at all of how the consumer might test or inspect pork for this pathogen.

    Having searched the net repeatedly for some consensus on the freezing procedure, I have found little more than there seems to be for cooking, except that, over the years, the depth and duration of the freezing has steadily increased, and the number mentions of this expedient decreased.

    As for the lack of detection methods – I can only wonder how Europeans deal with this problem when butchering and preparing wild boar – especially smoked meats.

    BTW – my wife loves raw fish preparations, and even a brief online survey of the number and nastiness of the parasites available from that food source sends me reeling. The only credible source on freezing as a remedy for fish parasites suggests that this would never be possible with anything but an industrial freezer, and even then would not be a sure thing.

    When I’ve asked sushi preparers about this, they simply declared their complete confidence in their suppliers of frozen fish. I would definitely like to see an in-depth article on raw fish preparation.

  • Stephanie Jenson

    Ed:

    Strangely enough, the night before your article came out, I had wonderful, thick, juicy pork chop cooked medium rare at Addy’s on Rockville Pike. The chop not only was true pink throughout, in the center it was, dare I say it, close to rare! No fear from the kitchen (I didn’t have to ask twice!) and a very normal thing for them to cook their pork chop MR. We were told at dinner Addy’s is comfortable doing this because they have a close relationship with their suppliers and the very high standards they and their local vendors follow.
    Best damn pork chop ever! And not a twinge of trouble…

  • Ed Bruske

    The original article was pretty narrowly focused on cooking pork loin. We’ve come to expect an answer and a lab test for everything under the sun. Obviously that’s not always the case. I’m sure there are some time-tested techniques for smoking pork. It would just be a matter of finding them.

  • kate hill

    As you know Ed, I work with small pork producers here in SW France where saucisson made from lean ham meat is barely cured and favored at the still soft stage- you could describe it as salted raw meat. The confidence in cooking comes from knowing your producer- the key to overcoming most the problems we have with fear and suspicion in food. Buying meat from a local producer or butcher who chooses his sources carefully means establishing relationships with the farmer and his work. We’re lucky here, where our producer’s market system has remained intact and uninterrupted for nearly 1000 years.
    Oh, and using nitrates and nitrites in artisan charcuterie? Severely frowned on here where proper salting, pepper and curing finish the seed-to-sausage production.
    As always- good work. thank you.

  • Sid

    In May of this year the USDA has lowered it’s recommendation for safe final temperature of pork to 145 with a 3 minute rest. Woot woot!

  • Jerry Cline

    I agree with the 135°F is optimum, but when a roast is cooked in water, as a base for a “stew” there is no such control. Sometimes the meat, even tho simmered in water for hours is tough and dry at the core. What is the solution (pun intended) to be able to have a tender, juicy and tasty boiled roast?

  • acuvic

    I was working in Germany a few years ago and as a treat for a job done “beyond the call of duty” we were taken to a restaurant in a remote place whose claim to fame was to serve rare pork. On questioning the manager on the safety of rare pork, he explain the intense focus on the food they were fed and pristine environment their pigs were reared under. With such perfectionist attitude of the German people, I felt safe to eat their fare. The pinkness of the pork servings added to the deliciousness of the meat and we had a great time. With no problems afterwards. Thought I ‘d share this experience as the discussion is about rare pork.

  • Ed Bruske

    I don’t think anyone is advocating “rare” or “bloody” pork,” just a little on the pink side and tender, rather than tough as shoe leather.

  • Neil Myers

    From the USDA:
    WASHINGTON, May 24, 2011 – The U.S. Department of Agriculture (USDA) is updating its recommendation for safely cooking pork, steaks, roasts, and chops. USDA recommends cooking all whole cuts of meat to 145 °F as measured with a food thermometer placed in the thickest part of the meat, then allowing the meat to rest for three minutes before carving or consuming.

    This change does not apply to ground meats, including ground beef, veal, lamb, and pork, which should be cooked to 160 °F and do not require a rest time. The safe cooking temperature for all poultry products, including ground chicken and turkey, remains at 165 °F.

    “With a single temperature for all whole cuts of meat and uniform 3 minute stand time, we believe it will be much easier for consumers to remember and result in safer food preparation,” said Under Secretary Elisabeth Hagen. “Now there will only be 3 numbers to remember: 145 for whole meats, 160 for ground meats and 165 for all poultry.”

    USDA is lowering the recommended safe cooking temperature for whole cuts of pork from 160 °F to 145 °F and adding a three-minute rest time. The safe temperature for cuts of beef, veal, and lamb remains unchanged at 145 °F, but the department is adding a three-minute rest time as part of its cooking recommendations. Cooking raw pork, steaks, roasts, and chops to 145 °F with the addition of a three-minute rest time will result in a product that is both microbiologically safe and at its best quality.

    Why the Rest Time is Important

    A “rest time” is the amount of time the product remains at the final temperature, after it has been removed from a grill, oven, or other heat source. During the three minutes after meat is removed from the heat source, its temperature remains constant or continues to rise, which destroys pathogens. USDA’s Food Safety and Inspection Service (FSIS) has determined that it is just as safe to cook cuts of pork to 145 °F with a three minute rest time as it is to cook them to 160 °F, the previously recommended temperature, with no rest time. The new cooking suggestions reflect the same standards that the agency uses for cooked meat products produced in federally inspected meat establishments, which rely on the rest time of three minutes to achieve safe pathogen reduction.

    Appearance of Cooked Pork

    The new cooking recommendations clarify long-held perceptions about cooking pork. Historically, consumers have viewed the color pink in pork to be a sign of undercooked meat. If raw pork is cooked to 145 °F and allowed to rest for three minutes, it may still be pink but is safe to eat. The pink color can be due to the cooking method, added ingredients, or other factors. As always, cured pork (e.g., cured ham and cured pork chops) will remain pink after cooking.

    Appearance in meat is not a reliable indicator of safety or risk. Only by using a food thermometer can consumers determine if meat has reached a sufficient temperature to destroy pathogens of public health concern. Any cooked, uncured red meats – including pork – can be pink, even when the meat has reached a safe internal temperature.

    For more information about raw pork, including storage information, see our fact sheet at http://www.fsis.usda.gov/Fact_Sheets/
    Pork_From_Farm_to_Table. Consumers can also “Ask Karen,” FSIS’ virtual food safety representative, at AskKaren.gov or m.AskKaren.gov (Mobile Ask Karen) on your smartphone. Mobile Ask Karen is a web-based app that makes “Karen” more accessible and adaptable to today’s on-the-go lifestyle. Now, Americans can take Karen with them – in the grocery store aisle, outside to the grill – anywhere you need information on food preparation or food safety tips. Just like using Ask Karen from a desktop or laptop computer, consumers can search for nearly 1,500 answers by topic or by product.

    The USDA Meat and Poultry Hotline (1-888MPHotline) has food safety experts available Monday through Friday from 10 a.m. to 4 p.m. EST (English or Spanish). Listen to timely recorded food safety messages at the same number 24 hours a day. Check out the FSIS Web site at http://www.fsis.usda.gov. E-mail questions can be answered by MPHotline.fsis@usda.gov.

  • Ed Bruske

    Thanks, Neil. We were aware of the change in the USDA recommendation–and not a moment too soon. As you can see from my post, chefs who really care about how their pork is served lean more toward an internal temperature of 135 or 140 degrees. The temperature rises some more if you let the meat rest a while. The USDA is more concerned about safety that culinary quality.

  • Carlos Danger

    Pulled a small 3 pounder that I marinated for 24 hours non-brine at 139, rested for 15 minutes.

    Tender, flavorful, delicious, light pink, clear juices.
    Carlos Danger can pull out on time.

  • Christopher

    Thanks very much for a well referenced, and thoughtful write up.

  • Don Zimmer

    I cook a pork butt roast until the internal temperature of the roast reaches 140 degrees F. Then, I remove it from the oven and wrap it lightly in aluminum foil and let it stand for 15 minutes. In my opinion, the roast is perfect; moist with a tinge of pink. Absolutely delicious. Because it was not overcooked, it still remains moist when I heat it the next day as a leftover. I can’t imagine cooking it until it reaches 160 degrees F. My wife did just that several months ago and the roast was as dry as a piece of leather. And the next day, the leftover roast was inedible.

  • Hans

    I agree with the author’s conclusion. Pork roast at 145 degrees is perfect. The meat is juicy and flavorful and still safe to eat.

    I have cooked pork roast at this temperature myself several times and have always been very satisfied with the results.

    So, if you want to make the perfect pork roast, you should cook it at 145 degrees Fahrenheit.

    I would also add that it is important to let the pork roast rest for at least 15 minutes before slicing. This will allow the juices to redistribute throughout the meat, resulting in a more tender and juicy roast.