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If you’ve ever shopped for milk, you’ve no doubt noticed what our questioner has: While regular milk expires within about a week or sooner, organic milk lasts much longer—as long as a month.
So what is it about organic milk that makes it stay fresh so long?
Actually, it turns out that it has nothing to do with the milk being organic. All "organic" means is that the farm the milk comes from does not use antibiotics to fight infections in cows or hormones to stimulate more milk production.
Organic milk lasts longer because producers use a different process to preserve it. According to the Northeast Organic Dairy Producers Alliance, the milk needs to stay fresh longer because organic products often have to travel farther to reach store shelves since it is not produced throughout the country.
The process that gives the milk a longer shelf life is called ultrahigh temperature (UHT) processing or treatment, in which milk is heated to 280 degrees Fahrenheit (138 degrees Celsius) for two to four seconds, killing any bacteria in it.
Compare that to pasteurization, the standard preservation process. There are two types of pasteurization: "low temperature, long time," in which milk is heated to 145 degrees F (63 degrees C) for at least 30 minutes*, or the more common "high temperature, short time," in which milk is heated to roughly 160 degrees F (71 degrees C) for at least 15 seconds.
The different temperatures hint at why UHT-treated milk lasts longer: Pasteurization doesn’t kill all bacteria in the milk, just enough so that you don't get a disease with your milk mustache. UHT, on the other hand, kills everything.
Retailers typically give pasteurized milk an expiration date of four to six days. Ahead of that, however, was up to six days of processing and shipping, so total shelf life after pasteurization is probably up to two weeks. Milk that undergoes UHT doesn’t need to be refrigerated and can sit on the shelf for up to six months.
Regular milk can undergo UHT, too. The process is used for the room-temperature Parmalat milk found outside the refrigerator case and for most milk sold in Europe.
So why isn’t all milk produced using UHT?
One reason is that UHT-treated milk tastes different. UHT sweetens the flavor of milk by burning some of its sugars (caramelization). A lot of Americans find this offensive—just as they are leery of buying nonrefrigerated milk. Europeans, however, don’t seem to mind.
UHT also destroys some of the milk’s vitamin content—not a significant amount—and affects some proteins, making it unusable for cheese.
There are, of course, lots of reasons people buy organic milk. But if it's the long shelf life you're after, I would recommend you buy nonorganic UHT milk and avoid being charged double.
*Correction (6/6/08): This sentence originally said "milk is heated to 145 degrees F (63 degrees C) for at least 30 seconds." (The error occurred during editing by the staff of ScientificAmerican.com and is not the fault of the expert.)
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49 Comments
Add CommentUHT milk is great stuff. It does take a while to get used to the taste, but it's perfect for making hot cocoa or lattes. Fresh milk is for drinking straight up.
Reply | Report Abuse | Link to thisLow temperature, long time is for 30 minutes, not 30 seconds as stated in the article.
Reply | Report Abuse | Link to thisSomeone should ask the public what they want
Reply | Report Abuse | Link to thisHOW MUCH SUGAR IS IN ONE SERVING--8 OZ.OF MILK ONE CUP ???
Reply | Report Abuse | Link to thisSomething tells me that James wants to know how much sugar is in an 8ox cup of milk.
Reply | Report Abuse | Link to thisAfter living in Europe for a while, and coming back to the Dairy state, I was saddened to find the milk I'd grown up drinking tastes flat and not unlike water with some goop in it. :( Unpasteurized milch is yummy!
It's still weird that we drink cows milk though. Weirder still is our gross-out reaction to the idea of drinking human milk... even though that's probably much better for us.
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Edited by hotblack at 06/06/2008 12:05 PM
At least two European countries are mainly using pasteurized milk: The Netherlands and Finland. And these are, if I am not mistaken, also the two European countries with the highest per-capita milk consumption.
Reply | Report Abuse | Link to thisUHT is a major step up in taste from the classical lower temperature sterilization. But indeed it still gives a tad of a "cooking taste" to the milk that is not appreciated by those of us that are used to the pasteurized variant.
One thing to note is that due to the very efficient process of manufacturing and distributing pasteurized milk in The Netherlands, most supermarkets can now sell fresh pasteurized milk with expiration dates 7-10 days in the future.
When I lived in Portugal, the only two types of milk available were the UHT boxed milk (we called in "atomic milk" just for fun) or raw unpasteurized milk in bags. We bought the UHT milk, but it never tasted very good. Neither seemed like a great choice at the time. But now, I would choose the raw milk. The fresher and least amount of processing the better taste and nutrition.
Reply | Report Abuse | Link to thisI assume it's because no one wants to drink it.
Reply | Report Abuse | Link to this--
Edited by jacomus d'paganus-fatuus at 06/09/2008 1:23 PM
I assume it's because no one wants to drink it.
Reply | Report Abuse | Link to this--
Edited by jacomus d'paganus-fatuus at 06/06/2008 3:53 PM
Locally, organic milk is about the same price as the other stuff, but the other stuff doesn't come in UHT format. It's cheaper for us to buy the organic UHT because we can't finish the non-organic before it goes bad.
Reply | Report Abuse | Link to thisIs there a safe home procedure for pasturisation of milk. To preserve the milk after milking for home use. Is there a non mechanical DIY home procedure for pasturisation, or small appliance for pasturisation. eMail: haroon.rashid@akunet.org
Reply | Report Abuse | Link to thisHere in the UK most milk is pasteurised and people don't like the "evaporated milk" flavour of UHT. I buy organic milk because it tastes better but it often goes off sooner than factory milk.
Reply | Report Abuse | Link to thisThere are several counter-factual statements in this press release, which you are passing off as "science." I'll wait for the lawyers to list them all for you, but in the meantime I'll point out that the organic milk brands we buy here in Massachusetts--including the one you picture in the article--are not UHT pasteurized, and that the Oregon tilth organic seal assures the use of organic feed for the cows (not merely the absence of hormones and antibiotics). Shame on you for passing off this garbage as anything other than an advertisement.
Reply | Report Abuse | Link to thisWho says milk is related to misery? That comment had nothing to do with the article. Lots of folks drink milk, but I cannot due to lactose intolerance. And, no, I am not going to take a pill to allow me to drink milk. Kinda counter-intuitive to me.
Reply | Report Abuse | Link to thisQuoting the bible is meaningless - if your daughter does not follow your rules, are you going to sell her as a slave?
(Exodus 21:7-11 NLT
Meaningless dribble.
I have to agree with hotblack and Jonathan on this one...
Reply | Report Abuse | Link to thisThe professor was unaware or unwilling to explain the real difference between organic and regular milk. Hormone-free milk, which is what the prof described, can be found in regular as well as natural and (obviously) organic. Organic milk is more about where the animal came from, the land it was raised on, the food it ate, and so on.
Also, I have been quite appalled at the fact that people go around suckling milk from other species, but nearly vomit at the thought of drinking our own. Although I prefer soy to human which is ALL TOO SWEET (excuse me for being curious...) I think that the health benefits have got to far outweigh when you do suckle from your own species.
Of course, who, of you mothers out there, would want to be a milk factory? That's what it really comes down to isn't it? Of course, there are wet nurses, so if there's $ in it...
So, if it isn't because of the type of pasteurization as Jon also stated, what is the reason? I figured it was because there was a lot less interference with the milk, but I could be wrong.
No matter the shelf life, if I could stand the taste, I would much rather prefer to drink organic milk. By the way, is anyone else worried about the supposedly soon coming cloned animal food? You think that'll include milk? Did you know that from what I've heard that the fda isn't requiring a label to inform us of which foods are cloned and which aren't? Some brands are already voluntarily stating they are clone-free.
I prefer organic, family farmed organic milk, which, as others have mentioned, is more than just hormone free, etc. It does seem to last longer, but I haven't noticed a sweet or caramelized taste to it, and the stuff I buy is refrigerated. It takes like I remember milk tasting. Others taste a little off to me, which makes me wary of them.
Reply | Report Abuse | Link to thisToo funny, UpQuark.
Reply | Report Abuse | Link to thisThe original poster was quoting a Quatrain from Nostradamus, not the Bible.
So typical. You think you're an expert and haven't even read the thing, just a few talking points from some anti-bible web sites.
Yup.. while I did make the error and freely admit it, I still believe that such quotes are beyond the mark and equally fruitless regardless of origin. I have often said, ' use the Google ' but in this case I did not head my own advice and I admit the mistake.
Buy organic and hope for the best?
Reply | Report Abuse | Link to thisRegardless, Nostradamus nor the bible nor the Qu'ran, it isn't science and all 3 are frivolous in my estimation.
As for the quotes, since you don't know me personally, I will allow your remarks. However, I grew up in that 'fire breathing God's wrath, burn in hell for thinking about girls' kinda environment. I know from what I quote and, now, as an adult find that type of belief inane.
What gets me about this article is that we have to be concerned, not about bacteria in our milk, but whether or not there is antibiotics or growth hormone etc within our milk. Yes, the label organic is a bit over the top, but there is a grain of truth to the drugs in milk. That is what bothers me most. What to do about it?
Exodus 21:11 -7
Reply | Report Abuse | Link to this7 "If a man sells his daughter as a servant, she is not to go free as menservants do. 8 If she does not please the master who has selected her for himself, [a] he must let her be redeemed. He has no right to sell her to foreigners, because he has broken faith with her. 9 If he selects her for his son, he must grant her the rights of a daughter. 10 If he marries another woman, he must not deprive the first one of her food, clothing and marital rights. 11 If he does not provide her with these three things, she is to go free, without any payment of money.
Sound pretty close to slavery to me (volition is not involved)
You can pasturize your own milk. Get a candy thermometer and stick it in the milk. Heat the milk to 160 degrees farenheit and hold it there for 15 seconds. Take it off the heat and sink the pan in a larger pan of cold water to cool it as quickly as possible. My mother did it for years after we had an episode of disease in one of my dad's cows and mother decided she wouldn't be responsible for making anyone sick.
Reply | Report Abuse | Link to thisWorks better than store pasteurization.
Sarah
Sorry, just had to delete a message that wasn't supposed to get posted.
Reply | Report Abuse | Link to this--
Edited by natikaal at 06/12/2008 2:29 AM
very nice article!
Reply | Report Abuse | Link to thisI disagree that "The process is used ... for most milk sold in Europe.". In a Times Online article (*) in only 7 of the 21 countries listed does UHT milk have a >50% market share.
Reply | Report Abuse | Link to this* http://www.timesonline.co.uk/tol/news/politics/article2658175.ece
joostdh, your figures are lacking. The median among countries is not the same as the average among liters. How much milk is consumed in those seven countries vs the rest, and in what proportion?
Reply | Report Abuse | Link to thisI did a bit of research and a bit of math. I got the UHT percentages by country from the article you cite, populations from http://en.wikipedia.org/wiki/Area_and_population_of_European_countries , and per capita liquid milk consumption from http://www.foodsci.uoguelph.ca/dairyedu/intro.html . The consumption data for (coincidentally) seven countries was missing (Belgium, Czech rRep, Denmark, Hungary, Norway, Poland, & Portugal) so I ran the figures both excluding those countries, and plugging in the EU average per capita consumption per the source above. For each country I calculated total milk drunk and total UHT milk, then totalled them all and found the overall percentage.
Excluding the countries with missing data: UHT = 52.4% of milk consumed.
Including said countries with EU average total consumption: UHT = 53.1%
Including them with an average per capita consumption (73.6l) calculated to bring the overall average per capital to equal the given EU average gives: UHT = 53.0%
I'm sure someone can find better numbers for those seven countries, but I don't think they can overcome the other countries for which I was able to find data, and still fit with the EU per capita consuption average.
I've never understood why the USA is so technologically backward. UHT milk has been available for at least 20 years all over the world - even in Africa! But it's still nearly impossible to find here, and when you do it costs more than the old fashioned kind. This despite the facts that it's cheaper to transport and store, takes up no space in the expensive refrigerated display cases, and tastes better too!
Reply | Report Abuse | Link to thisI suppose it's because UHT milk is sold by the liter and Americans are terrified of anything metric.
Actually organic has much more stringent criteria than you make out in your article, and since there is currently a battle over rBGH and whether or not farmers are allowed to advertise that they do not use rBGH on their cows, your readers should be fully informed. According to USDAs standards, milk and milk products can only be labeled organic if the milk is from cows that have been exclusively fed organic feed, are kept in pens with adequate space, are allowed periodic access to the outdoors and direct sunlight, are not treated with synthetic hormones and are not sick cows requiring that they have to be given certain medications or antibiotics to treat illness.
Reply | Report Abuse | Link to thisI think this is great info. Thanks.
Reply | Report Abuse | Link to thisThe article states that organic milk can last for up to a month. The article then states that regular milk that undergoes UHT does not need refrigeration and can last on the shelf for up to six months. Why would organic milk that undergoes UHT last for only a month (and maybe need refrigeration), but regular milk can last for six months without refrigeration?
Reply | Report Abuse | Link to thisI grew up in France and I only drank UHT as a kid. Now a parent, I really miss the convenience of it. I have not been able to find UHT at my local grocery stores. Where do you find yours????
Reply | Report Abuse | Link to thisWell! Here in Denmark, EU, the organic milk is heated to the roughly 71-75 degrees C (160-169 degrees F) NOT givin the UHT-treatment!
Reply | Report Abuse | Link to this- But still: Our organic milk lasts much longer.
Maybe you should find another 'expert'? ;-)
P.S.: The absolutly best taste of milk, is to find by the smal organic farmers, who sell milk at the farm.
When you by it right after milking, and kan get the milk directly 'from the cow', at (cow) body temperature, not pasteurized, not homogenized, not anything. I tell you: Thats heaven! :-)
P.P.S.: Why is "Conventionally grown" called Conventionally? When "Organic farming" is closer to the kind of farming humans have done trough the past 10,000+ years, and thereby should be called "Conventionally"???
John Johansen
Svendborg, Denmark
very strangely - sweeter is not the adjective my family or I would use for organic (non fat) milk. We tend to find organic (strangely) creamier than regular nonfat.
Reply | Report Abuse | Link to thisI accidently hit the report abuse button on Jonathan Feinberg post at 05:29 PM on 06/07/08. Please disregard this report. Sorry Jonathan, I actually liked your post.
Reply | Report Abuse | Link to thisFor those who laud unpasteurized milk in other countries: I've known fellow Americans who returned from trips to Europe who got debilitating disease from that "tasty treat."
Reply | Report Abuse | Link to thisAlso, even here - from the informative posts - I see that "not all milk is equal" from state to state.
I'm surprised to see all the variables affecting such a common food stuff. Thanks for the informative article, SciAm.
I have made my own homemade fresh yogurt ala Alton Brown from the Food Network. It turned out good using good quality pasteurized milk from a regional farm. I tried it with UHT organic milk and I ended up with warm, barely curdled milk. I was never sure why, but the lack of protein in UHT milk might provide the answer.
Reply | Report Abuse | Link to thisOrganic milk last so much longer than regular milk because of the vitamin E
Reply | Report Abuse | Link to thisOrganic farming is not just about pesticides and animal welfare. A Danish study shows that there are clear differences in content of organic and regular milk.
The study shows that organic milk is clearly healthier than conventional milk, because organic milk contains more antioxidants and vitamins than conventional milk.
Organic milk includes significantly more of the major vitamin E, which promotes milk durability. Vitamin E in the human body plays an important role in particular immune and cardiovascular disease.
Says research leader Jacob H. Nielsen from the Danish Institute of Agricultural Sciences in Foulum, Denmark.
And more: A Dutch study shows that Organic milk for pregnant women protect infants against allergies
Children whose mothers consume organic milk during pregnancy and lactation have less risk of developing asthma, eczema and allergic diseases.
John Johansen
Svendborg, Denmark
Similar studies have been conducted in the U.S. (Penn State, 2008) and found no nutritional differences between organic and nonorganic milk (Vitamin E was the same), no presence of antibiotics in either product (nonorganic farms can not ship milk from sick cows treated with antibiotics - every bulk tank is tested for presence of antibiotics before it leaves the farm), and no difference in hormone levels for both organic and nonorganic (these included all steriod hormones (estrogen) and growth hormone). Shelf life of organic milk is longer because of UHT...like the author states.
Reply | Report Abuse | Link to thisThe milk pictured is in fact UHT pasteurized. I worked as a UHT operator for a company that processed and packaged milk for Organic Valley, and we used the exact carton that is in the picture with the article. The specific carton pictured didn't come from the plant that I worked at - it has a different plant number - but I'm pretty sure that any other plant that processes milk for the company is held to the same standards.
Reply | Report Abuse | Link to thisOur UHT products had a shelf life of about 90 days from the date of package.
Like the above poster said, all milk deliveries were tested for antibiotics, and rejected if they contained any. The largest difference between raw organic and raw normal milk is the bacteria content. Raw organic milk has hundreds of times the bacteria of conventional milk, which is why it has to be ultra pasteurized. It wouldn't last a week on the shelf if it went through normal pasteurization.
As far as I know, it's illegal in the US to sell raw milk for consumption. There was a recent court case about a co-op group that sold shares of cattle and distributed the raw milk as dividends. They won the case from what I remember, but it's still illegal to package and sell raw milk for consumption.
How can you say the author is nonfactual when the carton says ultra pastuerized right on it? Hopefully you read the post from the person who actually worked at a plant that UHT pasuerized product for Organic Valley. I appreciated the author putting out factual information rather than the biased rubbish that leads consumers to believe that organic food is a much healthier product. I've been amused by the other posts to this article that state organic cows don't get sick. Oh they get sick alright, the producer just can't help them get better with antibiotics. How many parents would want to be told they shouldn't treat their sick kids with antibiotics or sick dog or cat? Where is the welfare of the animal in this discussion? I live next to an organic dairy that I would never drink the milk from...so to say they are pristine compared to conventional farms is not always the case. The bottom line is that milk is a very healthy drink whether it is organic or conventional. So much better than the soda, gatorade stuff parents are buying for the kids and themselves.
Reply | Report Abuse | Link to thisi have never liked the taste of 'conventional' milk. my parents could never get me to drink it as a kid. 3 years ago, i started buying organic, and it's been like night and day. i LOVE the sweetness and creaminess, and really appreciate the long shelf life, as i am away a lot and it doesn't go bad. it boils differently than regular milk, too. while i still think there are better sources of calcium, i feel pretty good about drinking milk now--so long as it's organic! i think the above poster's comment about antibiotics being 'good' is a bit misguided--we are too quick to use antibiotics for every little thing. i don't think children need antibiotics every time they get sick.
Reply | Report Abuse | Link to thisOMG I just poured Organic Valley's 1 % milk on my cereal and a large piece of cotton came out in the bowl!!!!! What should I do? I am sooooo grossed out as I already consumed this milk in my morning coffee! YUCK!
Reply | Report Abuse | Link to thisAccording to my pasteurized, 2% milk, it's 15 grams of sugar per 8 fluid 0z. of milk.
Reply | Report Abuse | Link to thisI agree. My parents usually buy pasteurized milk, and I invariably microwave a cup of milk for at least a minute before I drink it because I prefer the "cooked" taste, which tastes the same as the organic milk I've tried. It just tastes more toasty and a bit creamier... just like hot chocolate without the chocolate.
Reply | Report Abuse | Link to thisI am a dairy farmer and we sell our milk under our own label and we are not organic. Our milk is pastuerized normally. However, we get 18 days of code of the milk from the day it is processed, not 4-6 days like the article says. That is ridiculous. If you have a filler with the special HEPA filter you can get 18 days. Also, UHT allows for their to be more bacteria present in the raw organic milk to begin with. At our farm we strive to make the cleanest milk possible and are way under bacteria limits. Also, just because the UHT milk has a longer code doesn't mean that when you open it, it will last longer. It will have the same life span as pastuerized milk when it is opened. Do you really want to drink milk that has been sitting on the shelf for 2 months plus? No thanks!
Reply | Report Abuse | Link to thisOne more thing....no milk on the shelf will EVER actually contain antibiotics in it. Yes, the cows may have been treated for a short time if the have mastitis or another infection but the milk is dumped the entire time she is being treated and at least 3-5 days afterwards. We have to be 110% sure that her milk is clean before I can sell it. It is illegal to sell it if it has antibiotics in it and I will pay for the whole trailer load if I taint it. Trust me-every load and every farm is tested every pick-up. I am not an organic farmer. I feel that if my cow comes down with pnemonia the only thing proven to work is antibiotics so I am not going to let her suffer-I will treat her and dump her milk properly, and I do mean we kiterally dump her milk down the drain. If I have pneumonia I would certainly take penicillin. I wish some of you non-educated folks would actually go to a real dairy farm and see what really happens there and not just believe what people like PETA says. I am a dairy farmer and darn proud of it!
Reply | Report Abuse | Link to thisDecember 10,2009
Reply | Report Abuse | Link to thisMy eastern European ancestors have been drinking milk for thousands of years and it benefits me to do the same. I buy (low temp) pasteurized milk from grass fed cows. This is as close as I can get to drinking the milk my ancestors drank without having my own cow. It is sold in glass bottles and the only similarity it has to the milk in this article is they are both white. Only our Creator and our bodies know what nutrients are lost in all the modern processes.
Pasteurizing milk has enabled factory farms to produce cheap, safe milk at the expense of some lost essential nutrients. I can accept this and don’t think we can create a system to safely mass produce milk without pasteurizing at a low temperature. UHT milk is more like a dead version or chalk water. More heat is not better and bacteria is not always our enemy. Quick, cheap processing to make a non-refrigerated product does nothing for our health. I tell my family they are probably better off drinking water.
Homogenization scares me even more. Since milk is an oil and water combination, it doesn’t stay mixed. In this process milk is forced through tiny tubes, at about 3000 PSI to create small homogeneous (all of one size) fat molecules that prevent the fat from separating so a cream does not rise to the top. Our ancestors used to say “ummm” when they got a taste of the cream on the top of milk however, some where in the last 80 years some of us have learned to go “uhhhh”. When we drink homogenized milk an excessive amount of the proteins survive digestion in the stomach and are transported directly into the blood stream where they attack arteries. Some people believe homogenizing has greatly contributed to an increase in heart disease. Check out this link: http://www.realmilk.com/homogenization.html Others call it a rocket fuel for cancer. I have also read articles that when veterinarians give store bought milk to baby calves they get sick and often die.
I believe a glass of real milk has the best taste. and is a natural way to get vitamins, minerals, enzymes, probiotics, and God only knows what else, when cows are allowed to get out of the barns and do what is natural to them. We are what we eat and need to stop over processing.
Ken Kovach
The organic milk is more expensive, but in the long run, it costs me far less because I don't end up pouring out half a carton that has gone bad before I can drink it.
Reply | Report Abuse | Link to thisI don't notice a difference in the taste.
I also keep a couple of small cartons of UHT milk in the cupboard because it never fails when I am cooking and only need a half a cup or so . . we are out of milk. It comes in really handy when you only need a cup or less to cook with.
In your article you state the UHT process makes organic milk unusable for making cheese, but I have seen many Organic Cheeses on the market...how do they make these if your statement is true?
Reply | Report Abuse | Link to thisI wonder why it is that, every time I see a "scientific" article with a built-in bias against organic milk, I invariably find that the author has -- either past or present-tense -- received funding from Monsanto, the developer of the recombinant bovine growth hormone (rBGH) which is at the root of this controversy? Baumrucker, the author of this article, is no exception. Seems like there should be some sort of disclaimer attached to such articles, so that readers could know whether they're reading science or just more corporate-funded disinformation. It is no coincidence that there is as much vehemence devoted to discrediting organic milk as there is discrediting consumers who believe organic is better. The message we are supposed to hear is this: scientists -- even those on the payroll of the chemical and drug companies -- are the ultimate authorities on matters of food safety, and anyone who disputes them is either ignorant, naive and gullible or part of the tin-foil hat brigade.
Reply | Report Abuse | Link to thisCostco - you can get 3 half gallons for about 9 bucks... for the refrigerated - then the non-refridgerated they have also - for chocolate milk (and possibly white too- I can't remember) - I LOVE their KIRKLAND brand refrigerated milk.
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