Flour Milling

FLOUR MILLING

Technology

FLOUR MILLING American colonists in the seventeenth century introduced European grains along the eastern seaboard from Virginia to Massachusetts, built the first windmills and water mills, and developed New York as a milling and marketing center for flour. Until the mid-eighteenth century there was

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little reason for colonial mills to produce for other than local consumption.

England manipulated colonial trade with bounties, tariffs, and regulated markets that favored production of goods other than flour. The export trade was also limited by food needs in the colonies and the difficulties presented by transportation. Maryland, for example, feared famine and prohibited wheat and flour exports until 1740. After 1750 markets developed in the West Indies—particularly Barbados, Jamaica, and the Leeward Islands—because profitable sugar production there excluded almost all other husbandry. Between 1763 and 1766, Philadelphia exported 350,000 barrels of flour, mostly to the West Indies.

Colonial milling, whether by wind-or waterpower, involved much human labor. Stonedressing and mill-wrighting required skill, but carrying sacks of grain and flour called for constant heavy work. Since millers' tolls were usually fixed by law, the cost of labor figured importantly in profit and loss. Oliver Evans deserves credit for first engineering a mill in which grain and meal moved mechanically (completed 1785). His Young Mill-Wright and Miller's Guide, published in Philadelphia in 1795, described a continuous system of elevators, conveyors, and other automatic devices to process wheat "from wagon to wagon again." Evans's milling machinery constituted the beginning of automation in industry.

After the Revolution and until about 1830, Baltimore was the leading flour trade center in America. Its resources were abundant waterpower on the fall line, boat access to wheat lands in both the Chesapeake Coastal Plain and the Virginia Piedmont, millers who quickly adopted Evans's automatic machinery, and merchants who concentrated on the exchange of flour and grain for European manufactured goods. The wars of the French Revolution and Napoleon opened Britain's Atlantic ports to American goods. Baltimore merchants sold flour in England, the West Indies, and to the Duke of Wellington's army fighting in the Iberian Peninsula. This trade, and the resulting milling prosperity, lasted until 1814, when the British Corn Laws virtually shut off these markets.

While South American sales accounted for most American flour shipments from 1815 to 1860, the limited extent of the market justified little expansion in merchant milling. Important technological developments in farming, transportation, and grain storage, however, established the potential for rapid growth during and after the Civil War. Inventions of agricultural machinery allowed farmers to grow and handle grain in greater amounts: Cyrus McCormick's reaper (1831); John Deere's plow (1837); the Pitts brothers'—Hiram and John—thresher (1837); and William Pennock's grain drill (1841). The Erie Canal, opened in 1825, cut freight costs between the Genesee Valley and New York by 90 percent per ton. Railroads, from 1830 onward, tapped new agricultural lands. Improved transportation created a surplus of agricultural products that forced some farmers to specialize in wheat and others in dairy, vegetables, or livestock. Joseph Dart installed automatic machinery in his mills at Buffalo and applied steam power to operate grain storage elevators in 1843.

Before 1860 American millers ground soft winter wheat between millstones set close together. "Low" milling extracted as much meal as was possible from one grinding. Necessarily, the close grinding pulverized the wheat berry—bran, flour, germ, and all. Wheat germ enzymes and bran moisture impaired the flour's durability. By 1870, millers, particularly in Minneapolis, were experimenting with a European technique of "high" grinding and gradual reduction. This "new process" involved several (usually from three to five) grindings with the stones set progressively closer. The initial breaks stripped off the outermost bran covering and granulated the middlings (that part of the kernel between the inner endosperm and the outer pericarp layers). Bolting between grindings helped separate the bran from the flour. High grinding and gradual reduction produced a finer flour and more flour per bushel of wheat. Cadwallader C. Washburn, Charles A. Pillsbury, and George H. Christian took the lead in installing this most important advancement since Evans's automatic mill. Minneapolis flour shipments rose from 1 million to 5 million barrels between 1876 and 1884.

Hard spring wheat, grown increasingly in the Dakotas and Minnesota after 1865, required certain improvements in the gradual-reduction system. Besides its different growing habit, hard spring wheat had both a higher gluten content and a more easily shattered bran than the soft winter variety. Better grinding and separating methods were therefore necessary. In 1873 Edmund La Croix and George T. Smith, both in Minneapolis, patented middlings purifiers that separated the dust, bran, middlings, and flour more completely by blowing air through screens so meshed as to sort the different particles. Middlings purifiers actually date from well before 1873, but La Croix's patent improved the middlings grading arrangement while introducing the machine to America.

Chilled iron corrugated rollers began to replace millstones for grinding at about the same time the middlings purifier was introduced. Roller breaking, perfected in Hungary, twisted the grain rather than crushing or shearing it. It allowed more precise spacing between the grinding surfaces and more even stock-feeding than burrstones. The result was a more refined chop at each step in reduction. The first important American mill to use rollers was Washburn's in 1878. The main Pillsbury mill, in 1884, had a daily flour capacity of 5,000 barrels, using a steam-powered, automatic, all-roller, gradual-reduction system. Minneapolis flour shipments rose from 5 million to 10 million barrels between 1884 and 1894.

Several other inventions and adaptations improved overall plant operation. Germ scalpers—machines that sifted off wheat germ after flattening it out—came into use after R. L. Downton's invention in 1875. Carl Haggenmacher, a Hungarian, patented a plansifter in 1888 that improved the separation of the chop between grindings. O. M. Morse invented a "cyclone" dust collector in 1886 that reduced the hazard of explosions in mills. Electric power came into use in the operation of mills as early as 1887, in Laramie, Wyo., but steam-and waterpower predominated until about 1920.

The economies brought about by the automatic, allroller, gradual-reduction system favored those companies that adopted it first and on a large scale. Washburn, Crosby and Company; the Pillsbury Company; Northwestern Consolidated Milling; and Minneapolis Flour Manufacturing Company became leaders in plant efficiency and productive capacity. The large companies invested in projects supplying them with wheat: Pillsbury operated a string of grain elevators; Washburn helped project the Minneapolis–Saint Louis Railroad. Smaller mills could hardly compete with the industry's giants. During the depression of the 1870s many less efficient mills went out of business. The movement toward concentration created the "flour trust" in the 1890s. Thomas A. McIntyre organized the trust, the United States Flour Milling Company, in 1898, after acquiring mills and elevators in New York and Minnesota. Trusts, as management manipulations, more often brought excesses in unfair competition, price fixing, overcapitalization, and speculation than in improved products. The Sherman and Clayton antitrust laws helped curb the monopoly trend.

A decline in demand for flour in foreign markets and the growth of southwestern and Pacific Coast wheat regions geographically decentralized the milling industry. Europeans had developed their milling operations to the extent that they required more wheat and less flour from the United States. Between 1889 and 1899, wheat exports rose from 46 million to 139 million bushels. Kansas, Oklahoma, and Texas produced enormous quantities of hard winter wheat, while California and Washington grew large amounts of white wheat. Kansas City, Dallas, Seattle, and San Francisco developed as milling centers as well as grain markets. Buffalo, on the Great Lakes, took the lead from Minneapolis as the largest milling center after 1920. The Chicago Board of Trade became a major institution in the grain exchange. Wheat production continued to rise until shortly after World War I; during the Great Depression, both wheat production and flour consumption fell.

The development of quality-control procedures allowed product standardization, no matter where flour was manufactured or sold. Testing flour for strength and quality became standard procedure after A. W. Howard set up the first testing laboratory in Minneapolis in 1886. By the early twentieth century the major milling companies operated scientific laboratories not only to test the baking qualities of flour but to find industrial uses for wheat derivatives. Fabric sizing, dye thickeners, and paper adhesives derived from the starch, while low-grade gluten proved useful in waxes and paints.

Besides general-purpose flour, mills after 1900 manufactured breakfast cereals and special pastry, cake, and pancake flours—some including leavening ingredients. Marketing specialists realized that the best way to sell flour was to make it easy to use. General Mills introduced "Bisquick" in 1930 and followed with a variety of boxed, ready-to-use flour mixes. During World War II the National Research Council recommended that flour for military use be vitamin-enriched. Thereafter millers commonly added thiamine, riboflavin, niacin, and iron to household flour. The introduction of enriched flour reduced the incidence of some vitamin-deficiency diseases and eliminated others.

The most significant new advance in milling technology since the 1870s was made after World War II when engineers devised a mechanical system for refining flour, beyond ordinary milling, using airflow dynamics. Turbogrinders, introduced by Pillsbury Mills in 1959, generate high-velocity air vortices in which flour particles become smaller as they rub against each other. Air classifiers then separate the micron-sized particles into protein and starch fractions. With air grinding and classification, millers can process flours of two or three times the normal protein content.

Airflow systems have also been used in conveying and storing flour since the mid-1960s. Pneumatic conveyors have largely replaced bucket elevators, eliminating certain dust and insect problems, while making one-floor mill layouts possible. The pneumatic lines connect to storage bins and from there to Air-Slide railroad cars to facilitate bulk flour transportation.

Industry

Industrial history is in many respects typified by the history of American flour milling. Significant changes in market, in techniques of production, and in business organization, complicated by the rapid westward expansion of agricultural production and the relative uncertainty of the yearly amount and quality of the wheat crop, have marked the industry. Its dynamism is revealed by its rapid and wide changes of centers of production; its frequent shifting of equipment, capital, and labor; and its continuous and broad search for improved supplies of raw material.

The earliest English settlers brought small hand mills to America, but the growth of population and the expansion of wheat crops soon necessitated the construction of larger mills. After 1700, mills supplied with an abundance of wheat from the rich farmlands of the Middle Atlantic region met domestic needs as well as the demands of markets in Europe and in the West Indies. By 1750 Philadelphia was a leading flour center. Trade-conscious merchants purchased the products of nearby mills, hoping either to ship the barreled staple worldwide or to speculate on the domestic grain market, which in the 1750s became lucrative for the first time. By 1780 a combination of new technology, geography, waterpower, grain supply, and entrepreneurial skill had produced American milling centers of unusual capacity, such as the Brandywine Mills on Brandywine Creek near Wilmington, Del. This group of twelve "merchant mills" (so called because they ground specifically for export, as opposed to "custom mills," which supplied local needs) ground annually more than 50,000 barrels of flour of all grades—superfine, common, middling, ship stuff, and cornmeal. One-half of the total production was superfine flour.

Large-scale milling began with the growth of Baltimore and Richmond as milling centers in the first half of the nineteenth century. By 1860 Rochester, N.Y., supplied with the fine white wheat of the Genesee Valley, and Saint Louis and Milwaukee, supplied with the surrounding region's soft red winter wheat, were the leading flour-manufacturing centers. After 1870 the mills in Minneapolis burgeoned, aided by the concentration of wheat growing in Minnesota and the Dakotas, a ready source of waterpower in Saint Anthony Falls, and the invention of the middlings purifier, which made possible the milling of superior flour from spring wheat. C. A. Pillsbury and Company was organized in Minneapolis in 1874. In 1880, Minneapolis produced more than 2 million barrels of flour, and the local millers combined to form the Pillsbury-Washburn Flour Mills Company, the Northwestern Consolidated Milling Company, and the United States Flour Milling Company in an attempt to organize a monopoly of milling from hard spring wheat. The rapid spread of hard red winter wheat in Kansas and the Southwest encouraged the growth of milling in Kansas City in the 1890s.

Changes in the locations of wheat-growing areas and transportation, the introduction of the Alsop process of artificial bleaching in 1904, and the beginning of large-scale commercial baking have influenced milling since 1900. Cheap power, ready access to the great consumer markets, the opportunity to mill Canadian wheat in bond for export, and the relatively low freight rates for wheat on the Great Lakes speeded the rise of Buffalo, N.Y., as the leading milling center in the twentieth century. The growth of competition in flour marketing and changes in flour consumption stimulated the formation of such regional and national combinations as Pillsbury Flour Mills (1923), General Mills (1928), and Gold Dust Corporation (1929) and its subsidiaries.

Flour millers played an important role in conditioning public acceptance of the assembly line and the standardization of a dietary staple. It is not accidental that public attitudes concerning cleanliness, whiteness, color, and smell were conditioned by the improvement of milling techniques as they advanced from querns (primitive hand mills) to rollers and changed flour from an oily brown home-ground substance to a snowy-white one, mass manufactured by giant corporations.

BIBLIOGRAPHY

Giedion, Siegfried. Mechanization Takes Command. New York: Oxford University Press, 1948.

Lockwood, J. F. Flour Milling. Liverpool, New York: Northern Publishing, 1952.

Matz, Samuel. Cereal Technology. Westport, Conn.: AVI, 1970.

Storck, John, and Walter Teague. Flour for Man's Bread: A History of Milling. Minneapolis: University of Minnesota Press, 1952.

Welsh, Peter C. "The Brandywine Mills: A Chronicle of an Industry, 1762–1816." Delaware History, vol. 7 (1956).

G. Terry Sharrer

Peter C. Welsh / c. w.

See also Cereal Grains ; Cereals, Manufacture of ; Clayton Act, Labor Provisions ; McCormick Reaper ; Sherman Anti-trust Act ; Waterpower ; Wheat ; Windmills .