- Welcome everyone to Wednesday Nite @ the Lab. I'm Tom Zinnen. I work here at the UW-Madison Biotechnology Center. I also work for the Division of Extension, Wisconsin 4-H. And on behalf of those folks and our other co-organizers, PBS Wisconsin, the Wisconsin Alumni Association, and the UW-Madison Science Alliance, thanks again for coming to Wednesday Nite @ the Lab. We do this every Wednesday night, 50 times a year. Tonight, it's my pleasure to introduce to you Gina Mode and Ben Ullerup Mathers. They're both with the Center for Dairy Research and they're gonna be speaking to us tonight about buttermaking in Wisconsin. Gina was born in Fort Atkinson and grew up on a fifth-generation dairy farm. She graduated from Fort Atkinson High School and then came here to UW-Madison to study food science. She got her MBA from Edgewood College here in Madison, and she's been working at the UW-Madison since 1996. Ben Ullerup Mathers was born in Plymouth, Minnesota, which is a western suburb of the Cities. He went to Wayzata High School and then went to Macalester College in St. Paul, where he studied computer science and Chinese, which is an unusual combination. [audience laughing] He's been here at UW-Madison since 2021. Really looking forward to hearing about buttermaking in Wisconsin. It's a long tradition with a great future. Would you please join me in welcoming Gina Mode and Ben Ullerup Mathers to Wednesday Nite @ the Lab? [audience applauding]

- Ben: All right. All right. Thank you, Tom, for the introduction and thank you all for churning out tonight to listen to butter. We love talking about butter, so we're really excited to be here tonight. I'm going to start out by talking about the broad history of butter. There's a lot of minutiae that we're not going to be able to delve into just for the sake of time tonight, but I think we can establish an understanding of the development of butter and how it has led to the product we are so familiar with today. It's probably slightly apocryphal, but the first step for butter in its long journey started something like this. There's probably a shepherd who filled a bag with milk, slung that bag over the back or the neck of his pack animal, and then went on a long journey, possibly leading his herd to fresh pasture. When he arrived at his destination, he opened up that bag, and instead of finding the milk that he thought he put into it, he found beautiful golden kernels floating in a thin liquid. What had happened was that the prolonged agitation of the ride had churned the milk into butter and buttermilk. This newfound creation must have tasted good or at least been intriguing enough because people have repeated and refined this procedure for thousands of years.

But aside from enjoying the taste of butter, why would people even put in the effort to make butter from milk, right? When we think about food historically, a lot of times it's about survival. Well, one good reason to make butter is because it preserves milk. Raw milk can only last for a few days. Pasteurized milk lasts for a few weeks, but butter can last for months or years. How is this possible? Well, this extended shelf life is achieved through the standard methods common across most food preservation. Lowering moisture, right? Milk is usually 87% moisture thereabouts, whereas butter is between 15% and 20% moisture. By adding salt, sometimes historically, an excessive amount of salt as we'll talk about in a little bit. And through acidification, right, the addition or the creation of acid, and historically that would be traditionally done through fermentation. However, we can also turn milk into cheese, which unlike butter, a lot of cheeses taste better and better as they age, as opposed to butter, which really starts to decline after not too long, even though it can last for quite a while.

So why would someone choose to turn that milk into butter instead of cheese? Well, I think most importantly, they have very different culinary applications, right? What butter has that cheese doesn't have is that butter can be used as a cooking oil, and almost every cuisine relies on a cooking oil in order to elevate its flavors. So for cultures without ready access to other oils like olive oil, for example, in a lot of southern Europe, butter really was the most reasonable way to source this important ingredient of a cooking oil. You might be wondering what that very odd-looking lump on the right side of the screen is. That's actually, we're not gonna talk too much about it, but it's actually something called bog butter that they found in Ireland. This is butter that's been been preserved for over 3,000 years in bogs in Ireland. I don't know if you'd want to eat it, but in a pinch, you could probably choke it down.

So how do you get butter, right? I think this was a mystery to many people before us. They would take milk or cream and they would try to turn it, to churn it into butter. Usually it worked eventually, but sometimes it didn't. Even when it did work, sometimes it broke within a few minutes, and other times it would take hours to break that milk or cream into butter, and the flavor was not exactly predictable. This mystery of butter and buttermaking, combined with the important role many dairy products have played throughout cultures across the world, has led to a certain amount of mysticism and ritual surrounding this delightful spread that we know today. But this level of mystery and unpredictability is probably hard for us Wisconsinites, even as an adopted Wisconsinite, to understand. I would wager that most of us have a pretty narrow perspective of what butter is, right? For most of us, it is probably that convenient yellow stick that reliably spreads, melts, and delights, almost invariably made from the cream of cow's milk. But butter was not and is not even today as uniform as we think, and it has manifested itself in a myriad of ways throughout its long history.

So as an entryway into discussing this history of butter, this history of the production of butter, I want to talk about what we currently understand as normal butter, what we picture when we think of the word butter. It probably looks a lot like this, right? But what we don't often think of is that this is pasteurized sweet cream butter from cows, sometimes salted, sometimes unsalted. But what we need to understand about the butter that we eat is that although it is built on thousands of years of history, is in itself a relatively new invention. First, we can talk about the fact that it's sweet cream. What does that even mean? Maybe most of us don't know what sweet cream is or what the other options are. So we call it sweet cream in order to distinguish it from cultured cream or acidified cream. So if you think about the cream you buy at the store, if you took a sip of that, which I highly recommend doing. If you haven't done it before, it's really fun to taste the differences in creams, though people look at you weird. If you take a sip of that, it's mild, it's fatty, it has a creamy texture, and it has a faint sweetness to it, right? Not like a sugary sweetness in a brownie or a piece of cake, but there's a faint sweetness from that natural lactose that's in that product. 

By and large, this type of cream did not exist for most people until the 1900s. So why is that? Well, it starts with how you even get cream in order to churn into butter. The traditional way of getting cream from milk would be through something called gravity separation. Today, we use something called centrifugal separation, which we'll talk about in a little bit. But historically, for cow's milk, the traditional way to harvest cream is to let the milk set for several hours, sometimes overnight or possibly even several days. And the fat in that milk slowly rises to the surface in a process called creaming. You don't see this in the milk you buy from the store because it's been homogenized. That homogenization breaks up the fat molecules in that milk so that they don't break suspension. But if you don't have access to refrigeration, which for many people historically, the closest would've been a spring house, so a house built over a natural spring to keep it cool, or a cellar. And if you don't have access to pasteurization, which is another technique that would not be widely applied to dairy until around the 1900s. 

The other thing that's happening during this creaming separation process is acidification. The natural lactic acid bacteria in the raw milk, which again have not gone through pasteurization, so they haven't been destroyed, are eating the lactose in that milk and turning it into lactic acid, as well as a whole slew of other flavor-contributing compounds, some very delightful and delicious, others that might not be so much. So by the time you're ready to skim the cream off the top of that milk in order to churn it into butter, it has been acidified by these bacteria. It is tangy, it is sour, and it is teeming with these bacteria that have grown from the raw milk. In many cultures, that tanginess was traditionally one sign of a well-made butter. Raw cream butter still exists in several countries, but it's illegal in most of the United States. However, cultured butter, which seems to be growing in popularity, aims to capture similar flavors by taking pasteurized cream and then adding back the bacteria that we want in order to develop the acidity and flavors we desire. So if you look at this picture here, you can see the arrow is pointing to that line where on the top there's that whiter concentration of cream, really high-fat milk essentially. And then on the bottom is the skim milk that's a little less white. Just to be clear, 'cause this is a little, it's a little hard to see, it's the same idea with oil and vinegar, right? You could shake up this bottle and it'd be a beautiful emulsion. You set it on the counter, and eventually it's going to separate out again. This is just a picture of a spring house. Again, one of the early forms of refrigeration, but only if you're really lucky enough to have a natural spring on your property that you can build a house around. So this might be where people would put their milk while they're waiting for it to separate.

So that is all for cow's cream butter, right? That's for if we take the milk of cow and we wanna turn it into butter, we can use this gravity separation. However, cows are far from the only dairying animal in human history. Sheep, goat, water buffalo, yak, and more have all been integrated into different cultures for their delicious dairy. And all of these have had their milk turned into butter. However, not all milk gravity separates like cow's milk does. If you leave sheep or goat milk out for several days, it will certainly acidify like cow's milk will because of the native lactic acid bacteria in that milk, but it'll either not cream fast enough to skim for buttermaking, or it just won't cream at all. It's naturally homogenized. So if you wanna make butter from these milks of these animals, you have to churn the milk as it is instead of getting that higher concentration of fat in the cream. This is aided by the fact that most of these animals tend to have a higher fat content in their milk naturally than cow's milk does. But since you do not have to wait for the milk to cream, you could take the milk straight from the udder, cool it down a bit, and then churn it before much acidity is developed. So in terms of acidity, you could get something closer to the sweet cream butter that we know today, but it would still be raw, and it would still have those bacteria making changes over time as the butter ages, and it would taste different from, of course, the animal itself. If you've ever had sheep cheese or sheep milk, goat cheese or goat milk, these all have flavors that come along with them regardless of what you turn them into. But by using centrifugal separation, which is what I mentioned earlier, we can now take fresh milk from any species and separate the cream from the skim milk and churn that cream into butter in the same day.

So this centrifugal separation was invented in 1878, and you can see here, it is actually applied on a small scale for a while as well. This is a hand-cranked centrifugal separator in a very idyllic setting. I would love to make butter in the field with the cows. But this separator basically hastens the process of gravity that happens during that gravity separation, while also doing a much better job of separating the fat from that skim milk, giving us cream with a higher percentage of fat, which in turn will churn into butter faster. The higher fat in your cream, generally, the idea is that it will churn faster. So this process of centrifugal separation where we can take fresh milk and turn it into cream lickety-split is really one of the two cornerstones to the butter that is ubiquitous today because it made the buttermaking process so much more efficient and helped usher in that industrialization of butter. This is more commonly what you would see today when we think of a centrifugal separator. This is very similar to the one that the Center for Dairy Research has in our pilot plant. So it's more sophisticated significantly, but it's all the same premise behind it.

So the other cornerstone of the modern buttermaking process is pasteurization. Many of us know this, we've heard the term pasteurization probably since we were born. But pasteurization is the process of heating a product a certain temperature for a certain amount of time in order to significantly decrease the number of bacteria in the product. So for cream that you're going to turn into butter, the legal pasteurization parameters are either 185 degrees Fahrenheit for 15 seconds or 165 degrees Fahrenheit for 30 minutes. The destruction of most bacteria in the cream leads to a butter that will remain sweet. It won't acidify because those bacteria are no longer there to turn the lactose into lactic acid. Additionally, it will destroy any native lipases in the cream. So a lipase is an enzyme that breaks down fat into very aromatic, often potent, and in butter, often very unpleasant flavors. In cheese, we sometimes want that lipase to break down the fat. If you think of things like provolone, for example, there's this kind of stinky, strong note that comes from that lipolytic activity, but in butter, you don't really want it. So when you hear about fat going rancid, that rancidity is caused by that lipase acting on the fat. And historically, rancidity has been a huge problem for both buttermakers and butter eaters because the butter, again, was made with raw milk or cream and stored without refrigeration. But rancidity is more of a food quality issue than a food safety issue for butter. So rancid butter was often eated, sorry, excuse me, eaten by people. 

But people have always liked eating tasty food. So many solutions to this problem of rancidity were tested out. First, people sometimes horrendously oversalted their butter in order to try to preserve it more, right? These common techniques of the more salt you have, the longer something will last. And this did work to some extent, but the downside of it was that you have really salty butter. You wouldn't wanna eat this butter. So they would often soak it in cold water before using it in their cooking. The other option, which is just an extrapolation of this concept, was pickling butter. So submerging it in a salty brine just like you would for vegetables. But perhaps the most successful process to extend the shelf life of butter without rancidity was through the production of ghee. This was done very often in India. To make ghee, butter is melted and then boiled and strained through a cheesecloth. This effectively deactivates any lipases through the heating process, while also driving off residual moisture in the butter. So what is left is a clarified, lower moisture, and much more stable butter, often used more as a cooking oil than a spread. I personally don't like the texture of ghee on my toast, for example, 'cause it's a little gritty. But I can personally attest that I have had, like, a gallon of ghee that I made about a year ago, and it's still sitting on my counter. And it's definitely a little oxidized, which is a common defect in most butters, but it's far from rancid and it's never grown mold, and I still eat it because waste not, want not.

So with the advent of technology like centrifugal separation and pasteurization, it really was only a matter of time until buttermaking was industrialized. However, when we talk about the industrialization of butter, it's important to note how the societal change caused a change in the domestic order as well. In many cultures in Europe, Africa, and Asia, dairying fell into the realm of women's work. Dairy animals were often considered part of the household, and since the household fell under the woman's domain, dairying, including buttermaking, was part of the woman's role. This is why the term dairymaid has even persisted to this day. We've all heard that term. They were the ones who knew how to make the butter, store the butter, and sell the butter. And although women were initially included in the industrialization of butter because they were the ones who actually knew how to make it, so of course they had to be involved in setting up these large enterprises, they were eventually almost entirely excluded from the industry. Buttermaking had left domestic life, but women were largely still bound to the gender roles that kept them in the domicile, resulting in a lack of industrial women buttermakers. Thankfully, that is reverting now, right? And there are more women buttermakers, both in commodity butter and in the, once again, growing number of artisan buttermakers in the market.

We're gonna start churning the pages of history, right? The easiest pun we can make, but I love it. So we're just gonna go through several types of churns, and I just find it important to realize that when we talk about these methods of buttermaking, there's so many different specifics that you can use, so many nuances that are all trying to achieve the same thing. So this is a very common type of churn, probably one of the first types of churns. It's simply a tripod that you hang some sort of vessel from, and then you swing that vessel back and forth, filled with the milk or cream, until it breaks into butter. So this is an image of a woman using a gourd as that vessel. And here's another image, right, the same idea, but using a sheepskin bag instead. Of course, this is the plunger churn. This is the most commonly known old school churn when we think of the idyllic butter made in her natural habitat; this is what we think of. You simply fill that churn with cream, you put the plunger in, you put the lid on, and then you just thrust the plunger back and forth until it breaks into butter. Of course, a beautiful picture you can hang on your wall here.

Another common type throughout history was the paddle churn. So it's all the same idea, right? We're just trying to agitate this cream until it breaks into butter. And Gina's gonna talk a little bit more about the specifics of how that happens later. But the idea here is, you just suspend these paddles in the cream. You can turn them as fast as you can and it breaks into butter. This one is a hand-cranked one in a Mason jar. This is a larger one made out of a barrel, but the same idea within that. And then this is a version that's very commonly used in India. They have a little bit unique way of turning that paddle by using the ropes wrapped around the spindle of the paddle. But this is one of my favorite churns. The idea here is, it was marketed to housewives in the early 1900s, and the idea was that it could mimic placing a jar of cream inside the pouch of a kangaroo and then having that kangaroo hop around the field. And it was said that it could churn cream into butter in a minute and a half. So if you look up this video later, you can search exactly that, Kangaroo minute butter churn. It does a reasonably good job of mimicking that movement. 

And then this is a barrel churn. So this is most similar to the modern batch churn that we have today. You fill this barrel with cream, you crank the handle, and the cream splashes from one end to the other until it breaks into butter. This is, I like this one because this is a barrel churn that someone designed to get out of work so that they could put a dog in that treadmill to the right of the barrel and hang maybe a piece of meat above that dog so it continuously turns the treadmill and thus turns the barrel. So I like that; that's automation in work right there. And then there are a lot of other tools that were traditionally used in buttermaking. These are called butter hands. That's my favorite term for them, though they're also called butter paddles, which were used to work out more moisture from the butter. So you take that butter that you churn, it's still sopping wet with that buttermilk that it came from, and then you can work it more and you can work salt into it. And then you can shape it with these items here. 

This is a butter form or a butter mold. This was an especially important tool for different farmsteads in order to market their butter 'cause every farmstead would often have a specific design, a logo that they would imprint on their butter through the use of these molds. So you could go to the market, you could say, "Oh, I love the Swan butter. "It's made by Mrs. McCreary down the way. It's the best butter on the market. " And then this is something called a working table, which would be used with a similar intent to those butter paddles. You would put the freshly churned butter onto the table, and then you would crank that shaft in order to roll that pin back and forth across the butter, again, to change the texture of the butter, to distribute the moisture evenly, to work in salt, and to drive out a little bit of moisture. Another video that you should definitely watch when you have the chance.

This is a modern batch churn. I won't go too much into this 'cause Gina will talk more about these, but again, it looks kind of like the barrel butter churn. It's just a lot bigger; it's made outta metal. A little less work than cranking, hand-cranking or getting a dog to crank a barrel for you. And this is a continuous butter churn. Definitely the faster, more efficient version when it comes to modern churns. But they both have advantages, disadvantages, depending on what your operation looks like. We do just wanna mention, right, I talked about my ghee sitting out on a table for a year. Butter is a very safe food. It's made from pasteurized cream, pasteurized relatively high temperatures. It's a low moisture content like we talked about. It's a water and oil emulsion. There's often fat and there's often acid, either in the form of fermentation or added acid. Now, sweet cream butter is the exception to that in terms of the acid, but all those other ones hold true.

And we did wanna mention the butter/margarine war, especially living in Wisconsin like we do. The original form of margarine was actually invented in the 1860s in France due to the shortage and high cost of supplying butter to Napoleonic troops. It was a spreadable mixture with a beef tallow base. This might sound unappetizing to us, but due to the issues in butter quality that we mentioned earlier, it actually often tasted better than butter that was readily available on the market, and it was cheaper. This was actually an important moment in European buttermaking, and so by extension American buttermaking, because it drove an increase in quality because buttermakers knew they could no longer compete on a cost basis, so they had to compete on a flavor basis. Now, the modern margarine we know today is an extrapolation of this original idea. Once we could extract a greater number and volume of vegetable oils and to harden these oils to behave more like butter, animal fat was replaced by the cheaper and more readily available vegetable oils. And this was especially prominent during the World War II rationing, where butter was once again less available than we would prefer.

Now, once dieticians thought these margarines would be better for human health than butter since they had their origin in plants, and because animal products, especially fat, were increasingly looked down on in the health community. However, there's mounting evidence that appropriate amounts of animal fat, including butter, can have beneficial health outcomes in several areas. I think Gina will touch on that a little bit later. But despite the health consensus, many states did not take kindly to the mounting market threat towards butter that margarine posed. Some states mandated certain rules regarding the color of margarine. Butter is naturally a cream color, slightly to significantly yellow. And it is easy to color margarine, which is naturally white, to look almost identical to this butter. But some states mandated that margarine remain its pure white in order to not deceive customers into thinking that they were consuming butter, while other states even required the margarine to be colored pink or purple just to make it super clear that you're not eating a dairy product. [audience laughing] Unsurprisingly, Wisconsin was one of the states to outlaw yellow-colored margarine. It was not uncommon for housewives in the '50s and '60s to make joint margarine runs to either Minnesota or Illinois to stock up on the illicit goods. Yellow-colored margarine is now legal for sale in Wisconsin, but it is still illegal for a restaurant to serve margarine to a customer instead of butter unless the customer explicitly requests it.

This is the last slide of my part of the presentation before I turn over Gina. I just wanna share two of my favorite pieces of butter lore, which I bet you didn't think there is a ton of, but there is. [chuckling] The first story is of a very practical old woman in Ireland. She was being visited by an anthropologist who was observing her make butter. The cream was taking far too long to churn, so the woman went to the fireplace, drew out a hot poker, and thrust it into the churn. After a few more minutes, the cream broke into butter. Confused, the anthropologist asked her what had just happened. She explained that the fairies must have been hiding in the churn and playing around, trying to stop the cream from breaking into butter. So she had to scare them off with the hot iron poker. From her perspective, she successfully scared away the fairies with the hot iron. From our perspective, she significantly raised the temperature of the cream, and we know warmer cream will turn into butter faster. But both of our perspectives led to the same outcome. So who can say? Additionally, and this is truly my favorite one, in Sweden, Norway, and Ireland, there are tales of a milk hare, a rabbit constructed of wool sticks, fingernails, and skin that a witch could send off to neighboring dairies in order to drink up the milk straight from the cow's udder and return home with the bounty. The milk hare would then vomit the stolen milk into a bucket in front of its creator, who could then use that milk for her own nefarious purposes. So with that, thanks to these sources and these people, and I will turn it over to Gina.

- Okay; thank you, Ben. So I am also really excited to be here 'cause I get to talk about two of my favorite things: butter and Wisconsin. So why is Wisconsin the dairy state? Wisconsin has a unique combination of topography, soil, climate, and weather that is ideally suited for dairy. It is a lot like the dairying regions of Europe. But Wisconsin wasn't always the dairy state. In the 1840s to 1880s, Yankee settlers, English, Irish, and Scottish immigrants from New England had moved out to Wisconsin and grew cereal crops, particularly wheat in Wisconsin's fertile soil. Why wheat? Wisconsin had cheap, abundant land and wheat required little capital investment and was easy to grow. Simply plant it in the spring and harvest it in the summer and fall. Folks could farm cheaply and deliver a product that many people needed. In the 1850s, "As good as wheat," was a common phrase. Wisconsin became a state in 1848, and there were about 117 flour mills at that time to process the wheat that was being grown. The number of flour mills peaked at 700 in 1879. The mill pictured here was in Waupaca. All of the flour and lumber mills had streams, dams, and mill ponds for year-round water power. Today, we only have one flour mill remaining in Kenosha. Milwaukee was a major flour producer until the end of World War I. This is a picture of one of the Milwaukee flour mills.

So why the decline? The soil became depleted from planting wheat year after year. Plus in the 1860s, the crop was devastated by insects, chinch bugs to be exact, and the new railroad allowed wheat farming areas further west to compete. In essence, the Yankee farmers that had moved to Wisconsin from the northeast U. S. wore out the land and began moving further west. During this time, the farmers that remained in Wisconsin tried hops, tobacco, potatoes, and even sheep. The 1860s saw a large influx of European immigrants to Wisconsin: Swiss, German, Norwegian, French, Italian, and Dutch, populations who brought their traditions and skills with them. They concentrated on orchards and livestock. These new European settlers built barns for their animals. This was the advent of the red barns. And they prioritized animal care and recognized the importance of fertilizer. The manure from the livestock restored nitrogen to the soil, and utilizing crop rotation kept the soil fertile. In essence, the animals helped restore the value of Wisconsin farms.

We can't discuss dairy farming in Wisconsin without mentioning William Dempster Hoard. He is known as the father of American dairying. Hoard saw the decline in wheat yields and began a vigorous campaign to improve and grow the dairy industry. This was visionary at the time, and it was not easy to convince folks to embrace dairy farming. Pictured on the right is a statue of Hoard in front of Agriculture Hall on the UW-Madison campus. We'll talk more about the university's role in a minute. As we know, Hoard was successful. And this is a graph of the number of dairy cows in Wisconsin in blue and the milk production per cow in red. You can see that the number of cows exploded between 1867 and 1912, and peaked in 1945 at about 2.6 million. That's about the same number as the human population of the state that year. Dairy cow numbers are now steady at about 1.3 million, with the milk production per cow consistently increasing over time. 

As Ben mentioned earlier, butter was made mainly on farms until the mid-1800s. Then improved processing technology, including centrifugal cream separators, pasteurizers, and mechanical refrigeration contributed to the expansion of commercial creameries. And by 1900, butter was widely available throughout the U. S. The Industrial Revolution in the mid-1800s brought real specialization of labor. On farms, folks did everything. In factories, one person could concentrate on just buttermaking. This improved quality, which in turn brought a higher price in the marketplace. The photo on the right shows some wooden butter churns from the era. New York was the dominant dairy state from 1850 to 1910, with Wisconsin taking the lead in 1915. 

Many of the early influential dairy leaders, including Hoard and many at the University of Wisconsin, came from New York. This brings us to the role of UW-Madison. This is a photo of Ag Hall in the early 1900s. It was built in 1902, very different from how it looks today. I'm going to very quickly hit the brightest highlights of the dairy milestones at the University of Wisconsin-Madison because there were many. W. A. Henry came from Cornell to be the first professor of agriculture and went on to become dean of the College of Agriculture. He was instrumental in the other firsts listed here: the first experimental farm, farm institutes and corporate extension, farm short course, and formation of the UW-Madison College of Agriculture. Stephen Babcock also came from Cornell a few years later, and is known for developing the Babcock butterfat test to determine the fat content of milk. This test had far-reaching consequences. Milk had been paid for by weight, but some milk is more valuable because of higher butterfat content, which means it makes more butter and more cheese.

More importantly, individual cows could be tested to assist with breeding decisions, and the effects of feeds and nutrition could be measured. The Babcock butterfat test is still in use today. The first dairy school in the United States was established in Hiram Smith Hall. UW-Madison's first dairy building was constructed. This led to training courses in dairy manufacturing. These are great photos of some of the first classes. Note the butter churns in the photo on the left and the white dairy uniforms that are still traditional today. Remember that Wisconsin became the leading milk producer in 1915. It was also the first state to create rules and regulations ensuring clean milk was entering the marketplace. It's the only state to license butter makers. And by 1930, there were 517 butter factories dotting the landscape.

Next, a consolidation occurred due to technology improvements, which led to fewer, larger creameries. This was due to improvements in transportation from horse and buggy to trucks and electricity. Think refrigeration and pumps. Dairy processing was no longer completely manual. Production changes on the farm allowed for rapid expansion. By the 1950s, farmers began converting to refrigerated bulk tanks and then pipelines shortly thereafter. In the 1960s, farmers began installing milking parlors. The 1960s saw a massive conversion to bulk milk tanks and bulk trucks on farms, and this is what I remember from growing up. This is a video of 10-gallon milk cans, about 100 pounds each when full, being taken from a cistern and loaded into a truck. This was the method of cooling prior to bulk milk tanks. You can see the milk house being built in the background, and it already has an occupant. [audience laughing]

Technology improvements continued, and Wisconsin jumped from 1 billion pounds of milk in 1972 to over 2 billion in 1992. These are photos of the first Wisconsin mega dairy plant. It was highly automated and processed 2 million pounds of milk per day. This brings us to the modern era. Wisconsin's dairy industry is now $45. 6 billion annually and employs more than 150,000. The comparison to Florida's citrus industry and Idaho's potato industry really gives you perspective. And please note that that should say "Wisconsin dairy" under the wedge of cheese, not just cheese. Wisconsin produces 361 million pounds of butter each year and holds a premier position in the marketplace. It is currently home to 14 butter processing plants, 61 licensed buttermakers, and 78 licensed butter graders. Remember that Wisconsin is the only state to license buttermakers and require that all butter available for retail sale be graded. We talked about the big consolidation due to industrialization, and that happened across many industries in addition to buttermaking.

In the past several years, we've been really excited to see that Wisconsin has been experiencing a buttermaking renaissance. We're seeing more and more small, specialty, and artisan buttermakers bringing unique products to the marketplace. Due to an increase in demand, the CDR went from offering one butter short course every other year to offering up to four butter short courses each year. Nine of the current 61 licensed buttermakers earned their apprenticeship hours at the Center for Dairy Research over the last few years. During the short course, we get a lot of questions about the different types of butter. There are a lot of categories of butter, and these are the 39 that we cover in our short courses so far. The list gives our attendees lots of product development ideas. So what is butter? The definition and standards for butter in the U. S. were first set by Congress in 1886, and defined butter as: "The food product usually known as butter, "which is made exclusively from milk or cream or both, with or without common salt and with or without coloring matter." An act of Congress in 1923 added, "And containing not less than 80% by weight of milk fat, all tolerances having been allowed for." What I find most interesting is that the butter definition is both the oldest federal food standard and the shortest of all food laws.

Butter is one of the most highly concentrated forms of fluid milk. About 21 pounds of whole milk are needed to produce one pound of butter. This is about twice as concentrated as cheese. And an astounding one-third of the world's milk production is devoted to making butter. Here we see the composition of butter. There are three to four components, compositionally speaking. The milk fat content can vary from the legal minimum of 80% to about 86%, depending on the type. The moisture, salt, and curd, or milk-solids-not-fat can also vary by type. I included the composition of milk for reference to give you an idea of just how concentrated butter is. You can see that while the moisture is reduced from 87% to about 16%, the fat is concentrated from 3. 75% to more than 80%. It should also be noted that butter contains only trace amounts of lactose, which makes it different for most other dairy products. 

It's also important to mention pH, which is a measure of acidity, color, and consistency when discussing butter. The pH can vary depending on the type. Lowering the pH extends shelf life and gives the butter a tangy flavor similar to yogurt. The color can also vary. The golden color comes from betacarotene, and the amount of betacarotene in the milk depends on the type and breed of animal and their diet. For example, goat milk butter is very white while Guernsey cow milk butter is a rich gold. Consistency is also important. Butter should be firm when refrigerated, spreadable at room temperature, and melt in your mouth. So how is butter made? Very simply, butter is made from churning milk or cream. The churning process separates the solid butterfat from the liquid buttermilk. 

The definition of churning is to agitate or turn vigorously. These are the basic buttermaking steps, and we'll go into each in a little more detail. We begin with milk, and remember that the quality of the milk is the most important aspect of buttermaking. No matter how skilled the buttermaker, the butter can be no better than the milk from which it is made. Next, we separate the milk into skim and cream. This is the beginning of the concentration process for making butter. Some buttermakers do receive cream instead of milk, and their first step is pasteurization. Pasteurization of cream for buttermaking is required by law in the United States. The reasons for the high pasteurization temperatures for cream for buttermaking are threefold: to develop a highly desirable cooked flavor in the finished butter, to denature enzymes, specifically lipase, which causes rancidity, and as with all pasteurization, to inactivate spoilage bacteria and kill pathogens.

Cultured butter is created by adding a bacterial starter culture to the cream prior to churning. The culture ferments the lactose to lactic acid, which drops the pH and creates a tangy flavor. Cultured butter can be salted or unsalted. Tempering holds the pasteurized cream at a specific temperature for a specific time to allow the liquid fat that was created during pasteurization to migrate from the inside of the fat globule to the outside. We need the liquid on the outside for good churning efficiency. If you think about an M&M, the hard shell on the outside keeps them from sticking together, so they won't stick together. That's the same concept as the hard fat on the outside of the fat globule. So we want that liquid on the outside so that when they collide, they'll come together. The next step is churning. This can be done in a batch or continuous churn. Churning creates those collisions between the fat globules, leading to aggregation. 

The key to churning is phase inversion. We're moving from an oil-in-water emulsion to a water-in-oil emulsion. Our little Sprinkman batch churn is pictured here. The batch process is great for smaller volumes. It's easier to control the composition, and this is a great option for specialty and artisan buttermakers. Here we have the tempered cream on the left and the butter granules and buttermilk after churning on the right. The continuous method is the most common and works well when producing larger volumes of butter. The tempered cream is pumped into the upper chamber, where vigorous agitation with rotating beaters inverts the emulsion. The butter granules and buttermilk descend toward the augers, and the buttermilk is drained and the granules are washed. The augers work the butter into a continuous mass, and a vacuum at the end of the first set of augers removes trapped air and some moisture. 

At this point, water is added back to adjust the moisture. The salt or acid and flavor are added with this water. The second set of augers continue to work the butter and evenly distribute the ingredients. Then the butter is discharged. This is the separating section of a continuous churn, and you can see the granules and buttermilk falling down into the barrel, and the granules are moved along by the augers while the buttermilk drains out the bottom through a screen. The buttermaker can adjust the buttermilk level, the auger speed, and the beater speed. This is the vacuum section. It's designed to expose the maximum possible surface area of the butter, which allows the system to pull as much air out of the butter as possible. This will give the butter a closed body and longer shelf life.

There has been a lot of confusion surrounding the term buttermilk. The buttermilk coming off the churn is a byproduct of the butter manufacturing process and can be valuable as a commodity. Cultured buttermilk is an entirely different product. It is milk that has been fermented by bacteria to lower the pH and create a tangy flavor. The two are not interchangeable. Washing removes residual buttermilk and increases the shelf life of the butter. Here we can see washing of the butter granules in a large batch churn. On the right are butter granules ready for ingredients. Water can be added to adjust moisture, and lactic acid and natural flavor are added when making unsalted butter to lower the pH and extend the shelf life. This will also give unsalted butter a tangy, acidic flavor. Salted butter is what most of us grew up with. It's sometimes called American butter. And remember that salt is a flavor enhancer. The added salt will also give this butter a much longer shelf life.

Here you can see the butter ingredients being worked into the butter. The butter is becoming one continuous mass. Here we see moving the butter from the churn to the butter boat. It simply drops out of our little churn. And there's a video on the right showing how it drops into the butter boat in a larger churn. And there are many options, as you can see pictured here. This packaging machine can be used for rounds, half pounds, quarter pounds, pucks, or rolls. It was designed in the 1960s and can be adapted for many formats. It's one of the most common butter packaging machines in the U. S. It forms a pouch, fills it, folds it closed, and sends it on its way. It's for more traditional formats in premium products. It only takes about 40 minutes to change from one format to the next. And finally, we have storage. Butter can be stored at room temperature for up to a week, one to three months in the refrigerator, and 6 to 12 months in the freezer, depending on the type of butter and the conditions. And this is before the quality is affected. I'd like to stress that this is a quality issue, not a safety issue. Salted butter will last the longest. Unsalted, whipped, compound, flavored, cultured, homemade, not as long. Light, heat, and oxygen will have a detrimental effect on the quality. Also, butter is like a sponge and it easily absorbs odors from your kitchen or refrigerator.

So Ben touched on, is butter healthy? The pendulum has swung back and forth on butter, but all of the most current peer-reviewed scientific research states that it can be part of a healthy diet. Most recently, the European Society of Cardiology stated "that dairy, particularly whole fat, may protect against high blood pressure and metabolic syndrome." Here are just a few of the components of butter that have shown health benefits, but of course, butter should be enjoyed in moderation. And finally, I'd like to highlight some of our artisan buttermakers and the unique products they bring to the marketplace. Alcam Creamery makes hand-rolled, sweet cream, and whey cream butter. Whey cream is cream that is collected from the whey after the cheesemaking process and makes for a more flavorful butter. Carr Valley makes cow, goat, menage, and sheep cream butters. These are really unique. Nordic Creamery makes cultured, flavored, goat, summer, and unsalted butter. Summer butter is made from milk from cows eating fresh grass and hay during the summer months, and it will have a rich yellow color, grassy notes, and a softer texture. Organic Valley makes ghee, salted, and unsalted butter. Organic requires a minimum of 120 days of grazing per year, and it will have a rich yellow color and grassy notes. Pine River Dairy makes small batch churned, European style, flavored, lightly salted, and unsalted. European style is higher fat, and Pine River Dairy is known for their wide variety of flavored butters, including the award-winning sea salt caramel pictured here. Royal Guernsey makes flavored and salted butter from Guernsey milk. The extra betacarotene will give a richer, more golden color reminiscent of when Guernseys were common and known as the butter breed. 

Thank you all for joining us, and we encourage you to try some new butters the next time you have the opportunity. [audience applauding]