Hello friends! We are getting more in the depth of 20th century agricultural happenings in my class now, and I found a topic that might be of interest to you as well – namely, the history of the concern about the pasteurization of raw milk which is still topical today. I had only heard about the issue in little bits and pieces, so I thought it would be great to inquire further!
The entire story starts with the guy who the entire procedure is named after: Louis Pasteur. According to HowStuffWorks, he is known as the ‘father of microbiology’, inventing not only the pasteurization procedure, but also developing the germ theory of fermentation and discovering the vaccines for rabies, chicken cholera and anthrax. Cool dude.
In 1856, Pasteur discovered that fermentation was caused by microbes, and that the results of that process – e.g. whether grape juice became wine or vinegar – depended on the microbe present. Later, he was employed by Napoleon III to save France’s wine industry from being taken over by the ‘bad’ vinegar microbe, and realized that heating up the wine to a specific temperature for a specific time would kill the microbe and preserve the wine. He patented the procedure and called it ‘pasteurization’.
This procedure was then rediscovered by the dairy industry in the late 1800s and around the turn of the century because tuberculosis was rampant and often spread through contaminated milk. Robert Koch discovered that tuberculosis was caused by a bacterium and infectious, and not – as widely believed – inheritable, in 1882.[He also got a Nobel Prize for that discovery. NBD.] Other milk-borne illnesses included fever, diptheria, scarlet fever, anthrax and foot and mouth disease. Once scientists realized that a low-temperature, long-time heating of the milk (also called batch pasteurization) could kill the TB bacterium, governments pushed for the spread of this practice, and in particular the subsequently developed high-temperature, short-time (HTST) process (This is a good explanation of how heat kills bacteria, if you are interested, by the way).
The first law requiring the pasteurization of milk was passed in Chicago in 1908. Yet, there was a broad spectrum of opposition across the population, to the point that some producers adopted the practice in secret! In Sweden and Denmark, pasteurization on a commercial scale started to happen in the 1880s, and spread as interest in food safety picked up in Europe in the 1920s and 1930s, but farmers still opposed the practice of pasteurization, in particular because of the added costs they incurred. Furthermore, there were a huge variety of recommendations on how hot and for long you have to heat the milk in order to reliably kill bacteria.
Every procedure will have consequences for the milk, though. Today, you can differentiate between different types of milk processing: pasteurization itself refers to heating it to 72 – 74 degrees Celsius for 15 to 30 seconds. In comparison, UHT (ultra-high temperature) treatment goes up to 134 – 140 Celsius for 3 to 5 seconds. The higher the temperature, the more microbes you kill, but also the more the proteins within the milk are changed. This is why you may notice that the taste of UHT milk is different (it tastes ‘cooked’); other changes include how the milk reacts when making cheese, the color (the Maillard reaction can caramelize the sugars, turning the milk browner), and how long it can last without spoilage (since some protective enzymes may be destroyed as well). This is why pasteurization is preferred, according to HowStuffWorks: it “kills off the most heat-sensitive pathogens but retains the qualities of milk that consumers expect: creamy texture, fresh flavor and milky-white color.”
However, right now there is a revival of the debate over raw milk vs. pasteurized milk. In the US, for example, the sale of raw milk is legal in 28 states, though it cannot be transported across state lines. Here are some of the arguments of both sides:
– it protects the public from food-borne illnesses including salmonellosis, yersiniosis, E. coli-associated hemolytic-uremic syndrome (HUS), brucellosis, listeriosis, typhoid fever, Campylobacter enteritis, Q fever, and cryptosporidosis. Despite all safety precautions, raw milk still cannot provide the same guarantee. For example, “In just the first half of 2012, there have been 6 publicized outbreaks due to raw milk consumption in 8 states resulting in 152 illnesses and 4 hospitalizations (all children). In comparison, there were 7 raw milk outbreaks and 60 illnesses during all of 2011 […]. No outbreaks have been described from pasteurized milk in 2012. In 2011, one outbreak with 16 illnesses was linked to pasteurized milk from a dairy in Pennsylvania.” This is the account of the mother of one child which got E.coli after consuming raw milk.
– it still has basically the same nutritional content as raw milk.
– it extends the shelf life of the milk.
– pasteurization kills protective enzymes that prevent spoilage and help humans digest milk.
– heating milk destroys nutrients in it, particular vitamins C, some B vitamins, calcium and magnesium.
– Raw milk is indeed healthier: “Studies show that children fed raw milk have more resistance to TB than children fed pasteurized milk (Lancet, p 1142, 5/8/37); that raw milk is very effective in preventing scurvy and protecting against flu, diphtheria and pneumonia (Am J Dis Child, Nov 1917); that raw milk prevents tooth decay, even in children who eat a lot of sugar (Lancet, p 1142, 5/8/37); that raw milk is better than pasteurized milk in promoting growth and calcium absorption (Ohio Agricultural Experiment Station Bulletin 518, p 8, 1/33); that a substance present in raw cream (but not in pasteurized cream) prevents joint stiffness and the pain of arthritis (Annual Review of Biochemistry, 18:435, 1944); and that children who drink raw milk have fewer allergic skin problems and far less asthma than children who drink pasteurized milk (Lancet 2001 358(9288):1129-33).“
– producers of raw milk are better caretakers of cows, the land, and the milk, because they cannot “hide” bad practices by killing off all pathogens in their milk post-facto.
– pasteurization hasn’t actually helped prevent the outbreak of disease in all cases (which is supported by the statistics above I guess.)
Doing research on this topic, I found the debate to be very heated and emotional. So what to believe? I guess the truth lies somewhere in the middle, and the trade-offs (between food safety and food quality) are real. I’ve personally never had raw milk (except maybe one time as a kid on a farm? I have very hazy memories of not liking the taste though) and haven’t really made up my mind of which ‘side’ to stand on… I guess I’m with Michael Pollan who recognizes that “Raw milk is delicious and nutritious — and more risky to drink than pasteurized milk”. In fact, when answering readers’ questions on his website, here is what he had to say on the controversy:
Raw milk is delicious and nutritious — and more risky to drink than pasteurized milk. It also makes much more interesting cheeses, because some of the bacteria and enzymes destroyed during pasteurization contribute striking flavors. But producing raw milk safely takes a lot more care, and in recent years there have been several cases of people, especially children, getting sick after consuming raw milk.
There is a strong libertarian streak among many in the food movement, who demand the right to eat whatever they want, without interference from the government. They have a point — how is it that cigarettes are legal in this country while, in most states, raw milk can’t be sold in stores? On the other hand, doesn’t the government have a compelling interest in protecting children from a product about which they can’t make an informed decision?
You do have to wonder about the Food and Drug Administration’s priorities. Why is the government putting its resources into shutting down raw-milk producers, a teeny-tiny “industry,” when there are many more serious threats to food safety on factory farms? (In fact the overwhelming majority of illnesses tied to milk and cheese come from pasteurized products.) While Amish dairymen are being raided by the F.D.A., Jack DeCoster, the notorious Iowa egg producer whose filthy, salmonella-infected eggs were linked to an outbreak that sickened more than 1,500 people last year, received a mild warning letter from the F.D.A. What is going on here? Sounds like political theater to me.
What is your opinion? Do you purchase/drink raw milk?