Today's roller mills are an essential part of the American food production chain. Modern flour production depends on the use of grain roller mills to reduce wheat berries into flour. In addition, roller mills are vital to the processing of other grains, including the most important grain in the US today: corn.
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Understanding why roller mills have taken over the grain production industry requires an understanding of both the benefits of roller mills and the historical forces that worked together to give them an edge in the market.
Millstones: The Last Great Thing
Before roller mills, grain processing was done by millstones. Millstones were themselves a tremendous innovation and offered huge benefits when they were invented in the last millennium BCE.
Handheld grain grinder prior to the millstone.Before the invention of millstones, grain was ground using a variation on the metate: a handheld stone that was rubbed back and forth over an anvil stone. Not only was this method arduous, it resulted in the introduction of numerous rocks into the ground grain. This made the flour and any bread produced from it likely to damage a person's teeth. This is part of the reason why Egyptians needed so many dentists.
However, the Indians, Greeks, and Romans independently developed different forms of millstones. The millstone concept is similar to the metate: you have one stone that moves (often called the runner) while another remains stationary (called the sleeper or bedstone). Grain gets caught between the two stones and is ground down. At first, Olynthian runner millstones were moved by a lever over the bedstone. Later, Morgantina millstones were built in a rotary pattern. In Pompeii, relatively large mills were turned by levers pushed by slaves.
Millstone technology reached its peak when people began using wind or water power. This drove the mill better than human slaves or domestic animals could. At the same time, millstones were carved with intricate patterns of raised portions (called lands) and deep furrows, which progressed into finer channels called cracking. The pattern is divided into regular sections called harps or quarters.
Millstones could produce more flour and when the right stone was used, there was much less grit. Millstones were ideal for grinding the soft type of wheat grown in Britain and the Low Countries. Because they were so successful, millstones were used for nearly two millennia with few changes other than the motive power.
The Invention of Roller Mills
However, millstones were not as good at grinding hard wheat, AKA spring wheat, which was mostly grown in Eastern Europe and the US. This hard grain had a bran that tended to shatter in the mill, making it harder to separate from the ground flour. Retained bran tended to make the flour spoil. Not only that, but flour with too much bran had an unappealing appearance and taste. If flour made with spring wheat was to be shippable, storable, and palatable, a new method of milling was needed.
The origins of the modern roller mill begin in Europe. Swiss engineer Jacob Sulzberger began experimenting with roller mills in the s. His most successful installation was at Walzmühle, Budapest in Hungary. At this time, rollers were seen as a supplement to millstones. Stones were used for primary breaking of the grain, and the partly milled grain, called middlings or farina, then passed through rollers to be turned into flour. At Walzmühle, chilled cast-iron rolls were created in the local foundry for use in the roller mills. These rolls soon became the industry standard and were exported around the world through the 19th century. Some roller mills also used porcelain rollers, especially for processing semolina after stone grinding. By the s, corrugated iron rolls began to replace the stones at the early stages of the grinding process.
Industrialization Gives Roller Mills the Edge
As roller mills started to pop up, the ancient class of millers, who had long been prominent figures in local communities, began to see a threat to their status and livelihood. They tried to improve the effectiveness of millstones by modifying the patterns on them, but by this time the technology had largely reached its pinnacle, and they couldn't gain much productivity. However, they retained some advantage: running roller mills from water or wind sources required extensive gearing, which made them complex, noisy, and prone to failure.
With the spread of steam power and belt drives, it became easier to power roller mills. The mills themselves were also quieter, more efficient, and more reliable. The development of more advanced steel made rollers more effective and more durable. By the end of the 19th century, mills were being refitted with rollers and the millstones discarded.
The Breadbasket of Democracy
One of the major centers of milling that changed over to roller mills was Minneapolis, the flour capital of the US. As the population of the US grew through the 19th century, demand for flour skyrocketed, and mills needed to keep up. In the s, mills produced around 500 barrels of flour a day, but as the mills were changed into the much more efficient roller mills, productivity expanded dramatically. By the turn of the century, most mills produced barrels a day or more!
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This was due in part to the use of a series of rollers that created a gradual reduction of wheat berries into flour. Not only was the process more efficient, it produced a higher quality flour that could sell for much higher prices. This drove the expansion of mills to improve profitability.
Wheat production was in high demand during WW1The improvements were timely. They let US wheat production compete on the world stage. Soon, exports of US wheat made the country an essential trading partner around the world. The wheat was especially in demand during the World Wars when grain production in Europe was dramatically disrupted. It was around this time that Automatic Equipment Manufacturing entered the picture. By WWII, our mills were helping grind the flour that fed the soldiers who won the war.
Rolled wheat had been plagued by one disadvantage: it was less nutritious than stone-ground wheat. This is because the processes of rolling grain led to a better separation of the nutritious bran and germ from the wheat, processing the less nutritious endosperm into flour. This eliminates most of the iron, vitamin A, and vitamin B1 from flour. However, fortification of the flour made the rolled flour comparable to ground flour.
Roller Mills and the Rise of King Corn
But roller mills can process all types and sizes of grain, and the growth of roller mills is intertwined with the most important crop in the US today: corn (maize).
Corn is a grain native to the Americas, but it remained a relatively under-cultivated crop for centuries. In part, this was because it was an inefficient crop to grow. Corn yields per acre remained stagnant until the s when productivity per acre began to increase dramatically. This was due to two innovations: the hybridization of corn to make larger ears, and the development of industrial fertilizers that could satisfy corn's tremendous demand for nitrogen. Once corn productivity per acre began to soar, corn became more and more important as an animal feed.
Just in time, too, because by the time Americans returned from WWII and enjoyed the prosperity associated with their newly-won superpower status, they demanded more meat in their daily diet. As a result, corn demand also grew. From to , corn production grew about 8%. From to , corn production soared by 59%!
The spread of corn as animal feed was also facilitated by the development of highly efficient roller mills for cracking. These mills let farmers produce their own feed for a wide variety of animals, from chickens to cows.
Automatic high-capacity roller mill using PTO power.Roller mills became standard equipment at most farms. They were produced in small sizes for use by small family farms and in high-capacity models that helped farmers develop larger-scale operations so America could enjoy the plentiful supply of meat that made it the model of a prosperous democracy, leading to victory in the Cold War. The widespread use of electricity and the development of PTO systems with tractors helped make roller mills even more flexible and useful.
Today, corn is the most important agricultural product in the US. American farmers grow about 8 times more corn than wheat.
The History of Roller Mills Continues
An early Automatic Roller Mill, nearly 100 years ago.Today, Automatic Equipment Manufacturing continues to produce innovative roller mills. We draw on the extensive history of roller mills, including our own history that approaches a century of experience to make mills that incorporate the lessons of history to be efficient and durable. But we are also innovative, constantly seeking to make our mills produce better products, while becoming more efficient and easier to operate.
If you are looking for a roller mill to improve your farming or feedlot operation, we can help. Please contact Automatic Equipment Manufacturing today.
The story of the history of roller milling begins on mainland Europe, in Switzerland, during the s. There, a young engineer named Jacob Sulzberger reconstructed a mill in Frauenfeld. He installed a system of three rolls placed one on top of the other and, despite having flaws, it worked. He then went on to install roller machinery in Italy, Germany and Hungary with his installations at Walzmühle, Budapest, regarded as his most successful installation.
From these early advancements on mainland Europe, we then travel to England following the footsteps of Gustav Buchholz, a Prussian engineer who went to England in . He was a man who made many advancements, as regards roller machinery, but never quite made that final breakthrough, indeed one author described him as &#;on the verge of great accomplishments&#; throughout his entire career (Storck and Teague, p.228). He made a machine with six pairs of rollers in a single frame. Each roller had a sieve underneath to separate the finer and coarser particles and allow the coarser elements to progress to the next roller. This was the early beginnings of what would become the &#;break&#; section of the modern roller mill. His first installations were for Fison & Co., Ipswich in followed by Albert Mills, Liverpool in . Albert Mills claim to have been the first complete roller plant without stones in Britain as two years later, in , the stones were removed from the mill and slightly grooved rolls were installed. Despite having installed this machinery and patented his work, Buchholz&#;s designs never really had great success. In , Seth Taylor, a prominent London miller, described Buchholz&#;s work as &#;so elaborate, complex, and difficult in working that it had been a failure&#; (Simon, 175). Nevertheless, as he then goes on give him credit for &#;it had been the germ of the present roller milling&#;.
Instead, greater advances were happening back in Hungary where Abraham Ganz was pioneering the use of chilled cast-iron rolls. He had worked as a foreman in the Walzmühle foundry and started his own business in the s. This business became recognised as expert in chill-casting and it maintained this reputation after Ganz&#;s death in . He was succeeded by Andreas Mechwart who became head of Ganz & Co. and started making chilled iron rolls around which were then imported throughout the world.
Contemporary to the developments made by Ganz & Co. in Hungary was the work done by Friedrich Wegmann of Naples who invented a porcelain roller mill for reducing semolina and middlings. By the mid-s these machines could be found throughout Europe with the first arrival in Britain taking place at the end of . The impetus behind the trial of the machine in Britain can mainly be attributed to one man, Oscar Oexle. He had enlarged the Walzmühle workings in and then become an agent for Wegmann&#;s machines. During he wrote a series of articles in The Miller advocating the use of porcelain rollers and prompted a trial to take place in London in December . After this trial, around 30 machines were ordered in Britain and A. B. Childs was appointed Wegmann&#;s agent in Britain. By Wegmann claimed to have sold machines in Europe despite his machines not being as popular in Britain where the chilled cast iron rolls were more commonly used. Nevertheless, together these two inventions had a major impact on the milling industry in Europe and was the impetus the industry needed.
The story in America was slightly different and it is time to follow Oscar Oexle across the Atlantic as he visited the States in , again to promote the Wegmann porcelain rollers. Up to this point, the progression of the American milling industry had been quite different to that of Europe&#;s. The first impetus to make the industry more modern came from Oliver Evans who developed an automatic milling system during the s. These advancements were still a long way off the modern roller milling system but was nevertheless still responsible for making the industry more modern.
By the time Oscar Oexle arrived, almost 100 years after Evans&#; invention, there had been more developments than just mechanising the milling system. Indeed, one author describes that &#;We may think of the decade -80 as the period of &#;New Process&#; milling and that of -90 as the first decade of roller-milling&#; (Kuhlmann, p.125). So when Oexle arrived, America was in the midst of &#;New Process&#; decade, but what was &#;the principal factor in New-Process milling&#; (Storck & Teague, p.213)? It was the purifier. A purifier was a machine that is &#;used to extract the finest bran particles from the endosperm (flour)&#; to allow for &#;the maximum amount of flour&#; to be extracted from the wheat (Walker, p.11). The story of how it arrived in America, having travelled first from France to Canada, is an interesting one and highlights key individuals in the roller flour history of America.
The history of roller milling in America is really the history of roller milling in Minneapolis as the &#;great improvement in milling in this country started in Minneapolis&#; due to &#;a few broad-guage (sic) and liberal men who spent their money trying the experiments&#; (Gray, Part II, p.800). Two men in particular were C. C. Washburn and C. A. Pillsbury. C. C. Washburn had a varied career and, although not a miller himself, invested heavily into the industry, was prepared to take a chance and hired knowledgeable people. In he hired George Christian to run the Washburn B Mill. Christian was then responsible for bringing the purifier machine to the Washburn mill.
Nicholas and Edmund N. La Croix were French-trained engineers who, in , were induced to come to Montreal and build a mill for Alexander Faribault, a mill that would include a purifier machine. They also built one for John S. and George N. Archibald and it was their superior flour that caused Christian to try to find a way of replicating their method in the Washburn B mill. Edmund La Croix was hired and, in March , La Croix completed the purifier for the mill. Gray writes that La Croix &#;did not claim to have invented the purifier, but had copied it from a French book&#;, yet was nevertheless seen as an innovator in the States (Gray, Part III, p.844). This invention led the way for greater efficiency and productivity, but also a bitter legal dispute.
George T. Smith worked with Christian at the Washburn B mill. Once the purifier had been installed, he invented travelling brushes that could clean the sieves automatically rather than having to have a man stand by the machine to physically clean the sieves themselves. This, and other additions to the machine, were all patented by Smith and due to &#;patent wars, deals, and consolidations&#;, the machines were not freely available until (Storck and Teague, p.213). Around this time Smith left the Washburn B Mill and went to work for their competition, C. A. Pillsbury and Company, where he naturally installed the purifier machine so this &#;New Process&#; began to spread throughout the country. Indeed, by , 2,000 of Smith&#;s purifiers were in use whilst by , 19,000 had been sold.
However, George Christian and Washburn mills were not just responsible for introducing the purifier to America, they introduced other machines to the milling industry as well. In , a group of millers from Minneapolis visited Europe to view the &#;Hungarian milling process&#;. This group included both C. A. Pillsbury and George Christian. On his return, he started experimenting with roller machines and in , ordered 36 pairs of smooth chilled cast-iron rollers for the Washburn A mill. However, it was not until that a serious experiment with roller machinery took place after the Washburn mills suffered a great catastrophe. On 2 May , there was an explosion at Washburn A mill which killed 18 people and destroyed the entire premises. Not to be deterred, Washburn paced off land for a new mill to be built, the Washburn C mill, also known as the Washburn Experimental Mill. This mill was larger than the one which had been destroyed and a portion of it was set aside. In this area, W. D. Gray installed a 150-barrel-per-day roller system as the introduction of roller machinery properly started in the Sates. The explosion also highlighted the danger of flour dust as it was this highly flammable substance that caused the explosion. Future mills then ensured that dust collectors were installed in their mills.
Meanwhile, was an important year for the development of roller milling in Britain as well. During this year, the first all-roller gradual-reduction mill in Britain was installed for the McDougall Brothers in Manchester by Henry Simon. The previous year, Henry Simon had joined forces with Gustav Daverio and started selling his three-high roller machine. He used this in the installation at the McDougall Brothers mill. Three years later, Simon is credited as having installed a completely automatic roller flour mill for the same firm. Some claim this was the first completely automatic roller flour mill in the world, but others report J. Harrison Carter as having been the first when he installed an automatic roller mill for John Mooney in Dublin in . Nevertheless, the s saw the growth of roller milling in Britain as the newly founded National Association of British and Irish Millers (NABIM) encouraged the adoption of the machines on display at exhibitions, such as the one in Islington, London in , by companies, such as Henry Simon Ltd.; J. Harrison Carter; E. R. & F. Turner and W. R. Dell and Son. Roller milling in Britain was becoming an established system.
As seen in the Washburn mill, the s saw the beginning of the use of roller machinery in America as well. After fitting the Washburn C mill with roller machinery, Gray started to convince Mr. C. A. Pillsbury to install roller machinery. After having convinced his head miller, they tried to persuade Pillsbury who, &#;After a good deal of talk he very reluctantly told us to go ahead and change the mill, and added, &#;Go quick, for fear I&#;ll change my mind&#;.&#; (Gray, Part X, p.). The following day, the old machinery had been taken out of his Excelsior Mill and the new machinery put in. This machinery was proven to be a success and was eventually installed in all his other mills as well. So just as key men and companies were installing machines into big named companies in Britain, so they were also in America as W. D. Gray, with Edward P. Allis & Co., and John Stevens produced and installed machinery along with many others. The industry was growing both in Europe and America.
However, roller milling did not and does not solely exist in Europe and the United States. Countries throughout the world adopted the roller milling system and a selection of their histories can be read about in the following pages.
&#;Roller Milling: A Gradual Takeover&#;, From Quern to Computer: The History of Flour Milling.
Gray, W. D., &#;A Quarter-Century of Milling, Part II&#;, The Northwestern Miller (25 October, ), pp.799-800.
Gray, W. D., &#;A Quarter-Century of Milling, Part III&#;, The Northwestern Miller (1 November, ), pp.843-844.
Gray, W. D., &#;A Quarter-Century of Milling, Part X&#;, The Northwestern Miller (27 December, ), pp. & -.
Jones, Glyn, The Millers: A story of technological endeavour and industrial success, - (Lancaster, ).
Kuhlmann, Charles Byron, The Development of the Flour-Milling Industry in the United States (Boston, ).
Simon, Henry, &#;On the Latest Development of Roller Flour Milling&#;, Proceedings of the Institution of Mechanical Engineers Vol 40 (), 148-192.
Storck, John and Teague, Walter Dorwin, A History of Milling: Flour for Man&#;s Bread (Minnesota, ).
Walker, Graeme, &#;List of machinery in Caudwell Mill&#; (): CAUD-.
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