Are you sure about that ?
The Myths about Raw-Milk Cheese
By Janet Fletcher
Parmigiano-Reggiano, Roquefort and English Cheddar are among the most sought-after selections in any cheese case. But are they also among the most dangerous? Along with dozens of other raw-milk treasures—Fontina Val d’Aosta, Swiss Gruyère, Comté, Vermont Shepherd—these classic cheeses bear the weight of the myths and misperceptions surrounding raw milk. Some advocates suggest that raw-milk cheese is as safe as corn flakes—people aren’t dying like flies in Europe, are they? Yet others preach caution. With some physicians advising pregnant women to avoid all raw-milk cheese, consumers are wondering where the danger lies.
Does your cheese department staff know the raw-milk facts? Let’s examine some of the commonly held beliefs about pasteurization and its impact on milk, cheese and health. Anyone in the business of selling cheese needs to be able to tell the myths from the truth.
Myth 1: Pasteurized milk is sterile. Not true. If pasteurized milk were sterile, an unopened carton wouldn’t spoil. Pasteurization kills a lot of bacteria, including all the pathogens (disease-causing organisms) like Listeria and Salmonella and some but not all of the bacteria that make milk spoil. So pasteurization does make milk safer while it also increases the shelf-life.
There is more than one way to pasteurize. You can heat the milk to a high temperature (161 degrees F.) for a short time (15 seconds). Or you can heat the milk to a lower temperature (145 degrees F.) for a longer time (30 minutes). Most cheesemakers would say that the high-temperature, short-time (HTST) method does less damage to milk quality.
A third heat-treatment procedure, known as thermization or thermalization, stops short of pasteurization. This method preserves the milk enzymes while significantly reducing bacterial counts. The FDA considers thermalized milk as raw milk, so cheeses made with thermalized milk must still be aged at least 60 days.
Myth 2: Raw milk has more nutrient value than pasteurized milk. Not significantly. According to Moshe Rosenberg, food science professor at the University of California at Davis, vitamin loss from pasteurization is either too small to measure or less than 10 percent. The exception is vitamin C, which drops by about 20 percent.
Many people believe in the health benefits of raw milk’s enzymes. Pasteurization does denature enzymes, but according to Rosenberg, milk enzymes can’t withstand the low pH in the human stomach anyway. They don’t do anything for our digestion or health.
Myth 3: Pregnant women should avoid all raw-milk cheese. The concern here is Listeria, which can harm a fetus. So do physicians have science behind them when they tell pregnant patients to forego all raw-milk cheese?
Studies suggest not. Although high-moisture, unripened cheeses like cottage cheese and queso fresco and soft cheeses such as Brie and Camembert can support Listeria growth, aged raw-milk cheeses like Parmigiano-Reggiano, English Cheddar, Gruyère and Emmenthal cannot. They’re too dry, too low in pH, too high in salt. When Listeria turns up in cheese, it’s almost always in moist, soft cheese made with milk that was improperly pasteurized or contaminated after pasteurization. There have been several large outbreaks of listeriosis associated with Hispanic-style cheeses prepared under non-commercial conditions.
The FDA’s own risk assessment puts hard cheese last in Listeria potential among 23 common foods, including produce (www.foodsafety.gov/~dms/lmr2-toc.html).
From the standpoint of Listeria risk, it would make more sense to warn pregnant women away from fruits, vegetables or deli meats than to caution them about aged raw-milk cheese. Aged raw-milk cheeses are excellent sources of calcium and protein, needed by pregnant women.
The law requires raw-milk cheese—domestic or imported—to be aged at least 60 days at 35 degrees F. or above. By that point, most cheeses are no longer soft or moist, and are highly unlikely to harbor Listeria. (Some underage raw-milk cheeses do enter this country illegally, and pregnant women should avoid them.)
Myth 4: Raw-milk cheese tastes better than cheese made from pasteurized milk. That widespread belief comes under fire once you taste a Colston-Bassett Stilton, Spain’s luscious Nevat, a mountain Gorgonzola or the washed-rind Red Hawk from California’s Cowgirl Creamery—all from pasteurized milk. In the hands of a good cheesemaker, pasteurized milk does just fine.
Pasteurization does destroy some of the microflora in milk—the “bad” bacteria as well as the desirable flavor- and aroma-producing enzymes. Without these enzymes, cheese made from pasteurized milk has less potential for flavor development.
In one study, researchers at France’s Institut National de la Recherche Agronomique made the same cheeses from both raw and pasteurized milk. The raw-milk versions developed flavor sooner and the flavor was richer and more complex. The researchers’ conclusion: Pasteurization alters the biochemistry and microbiology of ripening and thus the texture and flavor of the cheese.
All things being equal, raw milk will produce a more complex cheese than pasteurized milk. Nevertheless, most cheesemakers would agree that fresh, high-quality pasteurized milk is better than low-quality raw milk any day.
Myth 5: Raw-milk cheeses aged more than 60 days are risk-free. Nothing we eat is risk-free. Cheese can be contaminated at any stage from farm to table: in the milking barn, in the dairy, in the aging room or at the retail counter. The 60-day rule, which dates from 1949, derives from the belief that pathogens can’t survive the low-pH, low-moisture environment of an aged cheese.
In fact, scientists have since shown that some pathogens—strains of Salmonella, Listeria and E. coli—can survive in cheese beyond 60 days. In most of these so-called challenge studies, they have inoculated pasteurized milk (not raw milk) with large quantities of pathogens—far more than you would find in quality milk—then made and aged the cheese. Lo and behold, in some cases, pathogens survived beyond 60 days.
Catherine Donnelly, a food microbiologist at the University of Vermont and an international expert on Listeria, believes that pathogens may behave differently in pasteurized-milk cheese than in raw-milk cheese. Says Donnelly, “Having lots of beneficial bacteria present is a good way to combat pathogenic bacteria. Once you eliminate all those good organisms, there’s nothing for the pathogenic bacteria to compete with.”
What do these challenge studies prove about aged raw-milk cheese, which has a remarkable safety record? In more than 50 years of scientific literature, there are virtually no reports of illness outbreaks from aged raw-milk cheese that can be blamed on the raw milk.
Myth 6: Mandatory pasteurization would make cheese safe for all. It’s true that pasteurization puts all known milk pathogens out of commission, but it doesn’t prevent milk or cheese from being infected downstream. In fact, it may make it easier, as Donnelly suggests. Not only can pathogens get a foothold when there aren’t any “good” bacteria to outcompete them, but dairies may relax their sanitary procedures when they know they’re working with pasteurized milk. One recent study of European washed-rind cheeses found almost twice as much Listeria in the pasteurized samples than in the raw-milk samples.
“The greatest threat posed to the safety of cheese is due to post-process environmental contamination,” writes Donnelly in a scientific paper. In that light, mandatory HACCP plans in dairies would probably do more to safeguard public health than mandatory pasteurization.
Specialty Cheese Series I - White Heat: Pasteurization vs. Raw-Milk Cheese
By James Mellgren
MARCH 01, 2005 -- The Online Quiz for this story is available in PDF format. Click here to download. -------------------------------------------------------------------------------- Science fiction movies produced in the 1950's and 60's often fantasized that in the future -- that is now, meals would be available in pill form. One pill would equal a steak dinner, while another would taste like spaghetti and meatballs. It was a very unappealing idea, at least to me, because it supposed that one simply ate to stay alive, rather than in my case, somehow managing to stay alive so I could eat again. So far, this culinary nightmare has not materialized, although we are perilously close with nutrition bars and dietary supplements, and yet decisions are continually made that would lead one to think that mere sustenance was the only reason we eat. Somehow, that quantity was infinitely more important than the quality and flavor of the food we eat. We are fortunate enough to be in a business in which flavor, craftsmanship, and tradition are held in high esteem, and indeed, are celebrated and exalted. Such is the case with cheese, a natural food that presents an inextricable link with our past and with tradition and with the earth. Made from milk, the very life source for us mammals, it comes in an amazingly wide variety of shapes, sizes, textures, flavors, and levels of quality. Just how that milk is processed, however, has become something of a controversy in the past couple of years, with terms like "artisan" and "raw milk" becoming catchphrases for foodies everywhere. They have also become virtual battle cries for cheese lovers across the land. For those of us who care about and make our livings from good food, the position is clear -- we want choice in what we eat and we want flavor.
Cheese of Choice When the FDA first announced that they were considering instituting a ban on all raw-milk cheeses, regardless of the cheese's age, the ensuing hue and cry reverberated throughout the specialty food business. A coalition was formed to bring sound scientific evidence to the debate and hopefully, ward off such action before it could possibly become law. The American Cheese Society (ACS), Oldways Preservation & Exchange Trust, and the Cheese Importers Association of America (CIAA) all banded together to form the Cheese of Choice Coalition, thereby bringing their formidable research and expertise to the front lines, as well as their connections to both the cheese-making and scientific communities. The idea of a ban on all raw-milk cheeses is a staggering thought for any cook or cheese lover. Think about not being able to buy Parmigiano-Reggiano, Grana Padano, Beaufort, Swiss Emmental, or English Farmhouse Cheddar, to name just a few of the great cheeses that would be outlawed under such a ban. At least for the time being, such a ban is unlikely, but fears of terrorism since 2001 have intensified the spotlight on raw-milk cheeses. According to the CIAA, the FDA's Center for Food Safety & Applied Nutrition (CFSAN) has given an 'A' priority (meaning that these are issues they expect to resolve this year) to the following cheese-related issues: - The issuance of draft guidance advising processors on steps to reduce the presence of Listeria monocytogenes in ready-to-eat foods. - Perform targeted inspections of dairy products manufacturers with an emphasis on raw milks, creams, butters and margarines, soft unripened cheeses, and fresh soft cheeses, - Develop an action plan to address the large-scale unlawful importation of cheeses, - Issue a field assignment regarding "gourmet" raw-milk soft cheeses, and - Complete the evaluation of the science of raw-milk cheeses and 60-day aging.
The 60-day aging refers to the current FDA law -- in effect since just after World War II -- that stipulates that any cheese made from raw milk must be aged for at least 60 days at 35° F before it can be released to the market, effectively making illegal such soft-ripened cheeses as authentic AOC Brie and Camembert and washed-rind cheeses, such as Pont l'Eveque, all from Europe. The theory behind the law is that dangerous bacteria like Listeria cannot survive in that environment for more than 60 days. Potentially a deadly strain of bacteria, Listeria is especially dangerous for pregnant women as it can severely damage the fetuses. For most of us therefore, it is a law we can live with. We make plenty of good soft-ripened cheeses here, and even though the French consume these cheeses all the time without incurring any problems, they don't have to ship them thousands of miles across the sea in order to do so. Lately, however, some dubious studies have suggested that some harmful bacteria might be able to survive longer than 60 days and therefore, could still be present in the cheese. Add to this some hysterical politicians who believe that raw-milk cheeses would somehow be easier for terrorists to infect than pasteurized ones. This supposes that once milk is pasteurized, it can no longer become contaminated. That is absurd. In fact, every single known case of cheese-related Listeria in this country has been positively linked to a pasteurized milk cheese. "There is always the potential for something like this to become law," cautioned Dun Gifford, president and founder of Oldways Preservation & Exchange Trust. "After all, it's in the interest of the cheese industry. They're armed with data that is outrageously wrong. It's not going to go away but in the end, they just don't have the studies to support their position and we do have studies to support ours." None of this is meant as a diatribe against pasteurized-milk cheeses. Like so many things that spur passionate debate, pasteurization and pasteurized cheeses are neither all good nor all bad. Methods of pasteurization have evolved in such a way that there exist many excellent examples of cheeses made from pasteurized milk although in every case it is when the process is guided by a thoughtful cheesemaker for whom the ultimate quality and flavor of the cheese are paramount. English Stilton, which is now required to be pasteurized, is a good example of a pasteurized-milk cheese that is nonetheless considered one of the world's great cheeses and is consumed with relish by gastronomes on both sides of the Atlantic. In fact, one need only attend a Fancy Food Show or an annual American Cheese Society Conference to see and taste dozens of splendid artisanal cheeses made from pasteurized milk.
Louis, Louis There is a certain irony to the fact that it was a Frenchman, Louis Pasteur (1822-95), who invented the process of heat-treating milk to destroy potentially harmful bacteria. Not because the French don't have pasteurized milk cheeses -- au contraire. In fact, the vast majority of Camembert made in France today is made from pasteurized milk. It's just that they don't have the restrictions on raw-milk cheese that we do, and they generally chide us because we do. In any case, Pasteur discovered the process during the course of his bacteriological research and it really is quite simple -- there are two methods, low heat and high heat, plus a third technique that some consider akin to using raw milk. - High heat: Milk is heated to 161° F, and held there for 15 seconds. - Low heat: Milk is heated to 145° F, and held there for 30 minutes. - Thermalization: This method requires the milk be heated at a very low temperature (one cheesemaker says he heats to approximately 150° F) for 15 seconds. Supposedly, this method leaves more of the useful, flavor-enhancing enzymes intact, although the FDA still considers it to be raw milk and regulates it as such. - Ultrapasteurization: This method, which requires heating the milk to 191° F for at least one second, is used mainly for fluid milk to increase its shelf life. Whatever method they employ, cheesemakers know that it does not make the milk sterile, nor does it significantly increase the shelf life (except in the case of ultrapasteurization). In other words, pasteurization shouldn't be dismissed out of hand, nor should it be considered a panacea, and in no way should it be used as a way to enhance inferior milk. Pasteurization will never make poor-quality milk better, or even safer. At the same time, however, good-quality pasteurized milk is better than poor-quality raw milk and vice versa. Confused? Don't worry, all of the specialty, artisanal, and farmhouse cheesemakers I've ever known or talked with take great pride in the quality of their milk and how they handle it, raw or pasteurized, and take their task very seriously. Those who assume that cheesemakers might be less vigilant because their milk is pasteurized simply don't know cheesemakers. Ricki Carroll explains in her book Home Cheese Making (Storey Books), "This heating process . . . destroys pathogenic bacteria, including Mycobacterium tuberculosis. As a public health measure for the sale of fluid milk, pasteurization has saved countless lives. As far as cheese making goes, it changes the flavor of the milk slightly and denatures four to seven percent of the whey proteins, which in turn generates a slightly weaker curd." "People begged us to do a raw-milk cheese," insists Brad Baird, owner of Celebration Farm and Still Meadows Cheese in Wisconsin (included in their cheese selection, he now makes a delicious raw-milk medium-sharp Cheddar). "Since we have control over the milk (they use only the milk from their own herd and two nearby farms with whom they are well acquainted), if there is any question at all about the health of the animal, we don't use raw milk. As far as flavor goes, I was really surprised at the taste difference between pasteurized and raw-milk cheese."
Raw-Milk Cheese at Store Level "We don't buy or not buy cheese based on whether or not it is made from raw milk," says Juliana Uruburu, the cheese manager at The Pasta Shop in Oakland and Berkeley, Calif. "We do put 'raw milk' on our signage, as well as cheat sheets for the staff. We also list the country of origin, whether it is organic or sustainable, and if it has been made with vegetarian rennet, some of which is more important to our customers than the raw-milk issue. Customers frequently ask if we have vegetarian cheese." "We sell one helluva lot of cheese here and I've had one request for raw-milk cheese in 35 years," insists Rita Shisler, owner of Shisler's Cheese House in Orrville, Ohio, and winner of the 2004 Small Business of the Year award. "Most of our cheeses are made with milk from the local Amish farmers. They use no chemicals or antibiotics, but it is pasteurized." Ultimately, we wondered what is a bigger factor, flavor or the health issues surrounding raw-milk cheeses? "Ninety-five percent of our pregnant customers won't go near them," recalled Uruburu, "but the other five percent do. We have a dozen or so customers who say they will only eat raw-milk cheeses because they insist the beneficial properties are more intact and therefore, the cheeses are healthier." Cheese authority and educator Debra Dickerson hears from both retailers and consumers about cheese-related issues and recently presented several American cheeses at the Slow Food Cheese Exhibition in Italy. "People who are educated about cheese seem to be asking more questions about the health angle," said Dickerson, "and not as much about flavor. At one time, people thought that raw-milk cheeses would taste better no matter what. They are more sophisticated now and have tried delicious pasteurized-milk versions. In fact, in Italy, we sampled out Mt. Tam (a washed-rind cheese from Cowgirl Creamery in Point Reyes Station, Calif.), not a raw-milk cheese. The people were stunned. Many of them were sure it must be a raw-milk cheese. It's a great tribute to American cheesemakers and what they have been able to do with one arm tied behind their back. Whether the cheeses are made from raw milk or pasteurized milk, at the end of the day, they'll go for the flavor. The challenge, as always, is to keep people tasting." Yes, in the end it is all about flavor. In that regard, it is the quality of the original milk and the cheesemaker's skill and desire, rather than whether or not it has been pasteurized that will determine how flavorful the cheese will be. By necessity, a typical cheese case in the United States will be a combination of raw and pasteurized cheeses. The key is to display them all proudly, use signage to tell the story of the cheeses, and let the customers' palates decide which ones are right for them. As long as we have a choice, and the consumers are well informed, all will be well in the Cheese Department. The challenge, as Dickerson so aptly put it, is to keep the people tasting, and I might add, to keep finding them new and exciting cheeses to taste.
"These are the foundations of quality and natural local variety in cheese: organically-farmed permanent grassland grazed by traditional dairy breeds (in winter, hay, not silage as food); strict hygiene in milking-parlor and dairy (exclusion of any milk given by cows under antibiotics…); traditional cheese-making methods using raw milk, and paying constant attention to acidity... This, I can promise you from rich experience, is the path to cheeses of incomparable aroma, flavour and succulence." -- Patrick Rance, from the forward to Cheeses of the World
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