A gristmill (also: grist mill, corn mill, flour mill, feed mill or feedmill) grinds cereal grain into flour and middlings. The term can refer to either the grinding mechanism or the building that holds it. Grist is grain that has been separated from its chaff in preparation for grinding.
The Greek geographer Strabo reports in his Geography a water-powered grain-mill to have existed near the palace of king Mithradates VI Eupator at Cabira, Asia Minor, before 71 BC. [1]
The early mills had horizontal paddle wheels, an arrangement which later became known as the "Norse wheel", as many were found in Scandinavia. [2] The paddle wheel was attached to a shaft which was, in turn, attached to the centre of the millstone called the "runner stone". The turning force produced by the water on the paddles was transferred directly to the runner stone, causing it to grind against a stationary "bed", a stone of a similar size and shape. [2] This simple arrangement required no gears, but had the disadvantage that the speed of rotation of the stone was dependent on the volume and flow of water available and was, therefore, only suitable for use in mountainous regions with fast-flowing streams. [2] This dependence on the volume and speed of flow of the water also meant that the speed of rotation of the stone was highly variable and the optimum grinding speed could not always be maintained. [2]
Vertical wheels were in use in the Roman Empire by the end of the first century BC, and these were described by Vitruvius. [3] The rotating mill is considered "one of the greatest discoveries of the human race". It was a very physically demanding job for workers, where the slave workers were considered little different from animals, the miseries of which were depicted in iconography and Apuleius' The Golden Ass . [4] [5] [6] The peak of Roman technology is probably the Barbegal aqueduct and mill where water with a 19-metre fall drove sixteen water wheels, giving a grinding capacity estimated at 28 tons per day. [7] Water mills seem to have remained in use during the post-Roman period.
Manually operated mills utilizing a crank-and-connecting rod were used in the Western Han dynasty. [8]
There was an expansion of grist-milling in the Byzantine Empire and Sassanid Persia from the 3rd century AD onwards, and then the widespread expansion of large-scale factory milling installations across the Islamic world from the 8th century onwards. [9] Geared gristmills were built in the medieval Near East and North Africa, which were used for grinding grain and other seeds to produce meals. [10] Gristmills in the Islamic world were powered by both water and wind. The first wind-powered gristmills were built in the 9th and 10th centuries in what are now Afghanistan, Pakistan and Iran. [11] The Egyptian town of Bilbays had a grain-processing factory that produced an estimated 300 tons of flour and grain per day. [12]
From the late 10th century onwards, there was an expansion of grist-milling in Northern Europe. [9] In England, the Domesday survey of 1086 gives a precise count of England's water-powered flour mills: there were 5,624, or about one for every 300 inhabitants, and this was probably typical throughout western and southern Europe. From this time onward, water wheels began to be used for purposes other than grist milling. In England, the number of mills in operation followed population growth, and peaked at around 17,000 by 1300. [13]
Limited extant examples of gristmills can be found in Europe from the High Middle Ages. An extant well-preserved waterwheel and gristmill on the Ebro River in Spain is associated with the Real Monasterio de Nuestra Senora de Rueda, built by the Cistercian monks in 1202. The Cistercians were known for their use of this technology in Western Europe in the period 1100 to 1350.
Although the terms "gristmill" or "corn mill" can refer to any mill that grinds grain, the terms were used historically for a local mill where farmers brought their own grain and received ground meal or flour, minus a percentage called the "miller's toll." [14] Early mills were almost always built and supported by farming communities and the miller received the "miller's toll" in lieu of wages. Most towns and villages had their own mill so that local farmers could easily transport their grain there to be milled. These communities were dependent on their local mill as bread was a staple part of the diet.
Classical mill designs are usually water-powered, though some are powered by the wind or by livestock. In a watermill a sluice gate is opened to allow water to flow onto, or under, a water wheel to make it turn. In most watermills the water wheel was mounted vertically, i.e., edge-on, in the water, but in some cases horizontally (the tub wheel and so-called Norse wheel). Later designs incorporated horizontal steel or cast iron turbines and these were sometimes refitted into the old wheel mills.
In most wheel-driven mills, a large gear-wheel called the pit wheel is mounted on the same axle as the water wheel and this drives a smaller gear-wheel, the wallower , on a main driveshaft running vertically from the bottom to the top of the building. This system of gearing ensures that the main shaft turns faster than the water wheel, which typically rotates at around 10 rpm.
The millstones themselves turn at around 120 rpm [ dubious ]. They are laid one on top of the other. The bottom stone, called the bed, is fixed to the floor, while the top stone, the runner , is mounted on a separate spindle, driven by the main shaft. A wheel called the stone nut connects the runner's spindle to the main shaft, and this can be moved out of the way to disconnect the stone and stop it turning, leaving the main shaft turning to drive other machinery. This might include driving a mechanical sieve to refine the flour, or turning a wooden drum to wind up a chain used to hoist sacks of grain to the top of the mill house. The distance between the stones can be varied to produce the grade of flour required; moving the stones closer together produces finer flour.
The grain is lifted in sacks onto the sack floor at the top of the mill on the hoist. The sacks are then emptied into bins, where the grain falls down through a hopper to the millstones on the stone floor below. The flow of grain is regulated by shaking it in a gently sloping trough (the slipper) from which it falls into a hole in the center of the runner stone. The milled grain (flour) is collected as it emerges through the grooves in the runner stone from the outer rim of the stones and is fed down a chute to be collected in sacks on the ground or meal floor. A similar process is used for grains such as wheat to make flour, and for maize to make corn meal.
In order to prevent vibrations from the millstones shaking the building apart, they were usually placed on a separate timber foundation, not attached to the mill walls, known as a husk. This foundation isolated the building from vibrations coming from the stones and main gearing and also allowed for the easy re-leveling of the foundation to keep the millstones perfectly horizontal. The lower bedstone was placed in an inset in the husk with the upper runner stone above the level of the husk.
American inventor Oliver Evans revolutionized the labor-intensive process of early mills at the end of the eighteenth century when he automated the process of making flour. His inventions included the Elevator, wood or tin buckets on a vertical endless leather belt, used to move grain and flour vertically upward; the Conveyor, a wooden auger to move material horizontally; the Hopper Boy, a device for stirring and cooling the newly ground flour; the Drill, a horizontal elevator with flaps instead of buckets (similar to the use of a conveyor but easier to build); and the Descender, an endless strap (leather or flannel) in a trough that is angled downward, the strap helps to move the ground flour in the trough. Most importantly, he integrated these into a single continuous process, the overall design later becoming known as the Automatic (or Automated) mill. In 1790 he received the third Federal patent for his process. In 1795 he published "The Young Mill-Wright and Miller’s Guide" which fully described the process. [15]
Evans himself did not use the term gristmill to describe his automatic flour mill, which was purpose designed as a merchant mill (he used the more general term "water-mill"). In his book his only reference to "grist" (or "grists") is to the small batches of grain a farmer would bring in to have ground for himself (what would be generally called barter or custom milling). In his book, Evans describes a system that allows the sequential milling of these grists, noting that "a mill, thus constructed, might grind grists in the day time, and do merchant-work at night." [16] Over time, any small, older style flour mill became generally known as a gristmill (as a distinction from large factory flour mills).
Modern mills typically use electricity or fossil fuels to spin heavy steel, or cast iron, serrated and flat rollers to separate the bran and germ from the endosperm. The endosperm is ground to create white flour, which may be recombined with the bran and germ to create whole grain or graham flour. The different milling techniques produce visibly different results, but can be made to produce nutritionally and functionally equivalent output. Stone-ground flour is preferred by many bakers and natural food advocates because of its texture, nutty flavour, and the belief that it is nutritionally superior and has a better baking quality than steel-roller-milled flour. [17] It is claimed that, as the stones grind relatively slowly, the wheat germ is not exposed to the sort of excessive temperatures that could cause the fat from the germ portion to oxidize and become rancid, which would destroy some of the vitamin content. [17] Stone-milled flour has been found to be relatively high in thiamin, compared to roller-milled flour, especially when milled from hard wheat. [17]
Gristmills only grind "clean" grains from which stalks and chaff have previously been removed, but historically some mills also housed equipment for threshing, sorting, and cleaning prior to grinding.
Modern mills are usually "merchant mills" that are either privately owned and accept money or trade for milling grains or are owned by corporations that buy unmilled grain and then own the flour produced.
One common pest found in flour mills is the Mediterranean flour moth. Moth larvae produce a web-like material that clogs machinery, sometimes causing grain mills to shut down. [18]
A windmill is a structure that converts wind power into rotational energy using vanes called sails or blades, by tradition specifically to mill grain (gristmills), but in some parts of the English-speaking world the term has also been extended to encompass windpumps, wind turbines, and other applications. The term wind engine is also sometimes used to describe such devices.
Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many cultures. Corn flour has been important in Mesoamerican cuisine since ancient times and remains a staple in the Americas. Rye flour is a constituent of bread in both Central Europe and Northern Europe.
A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of many material goods, including flour, lumber, paper, textiles, and many metal products. These watermills may comprise gristmills, sawmills, paper mills, textile mills, hammermills, trip hammering mills, rolling mills, wire drawing mills.
A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel, with a number of blades or buckets arranged on the outside rim forming the driving car. Water wheels were still in commercial use well into the 20th century, but they are no longer in common use today. Uses included milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, ore crushing and pounding fibre for use in the manufacture of cloth.
Millstones or mill stones are stones used in gristmills, used for triturating, crushing or, more specifically, grinding wheat or other grains. They are sometimes referred to as grindstones or grinding stones.
Bale Grist Mill State Historic Park is a California state park located in Napa County between St. Helena and Calistoga. The park is the site of a water-powered grist mill that was built in 1846 is one of only two water-driven mills remaining west of the Mississippi River.
A millwright is a craftsperson or skilled tradesperson who installs, dismantles, maintains, repairs, reassembles, and moves machinery in factories, power plants, and construction sites.
A mill is a device, often a structure, machine or kitchen appliance, that breaks solid materials into smaller pieces by grinding, crushing, or cutting. Such comminution is an important unit operation in many processes. There are many different types of mills and many types of materials processed in them. Historically mills were powered by hand or by animals, working animal, wind (windmill) or water (watermill). In modern era, they are usually powered by electricity.
A miller is a person who operates a mill, a machine to grind a grain to make flour. Milling is among the oldest of human occupations. "Miller", "Milne" and other variants are common surnames, as are their equivalents in other languages around the world. Milling existed in hunter-gatherer communities, and later millers were important to the development of agriculture.
Watson's Mill is an historic flour and gristmill in Manotick, Ontario, Canada. It is the only working museum in the Ottawa area and one of the very few operating industrial grist mills in North America. Watson's Mill still sells stone-ground whole wheat flour which is made on site. The mill is also well known for its ghost Annabelle. The legend is that Ann Currier, wife of Joseph, haunts the mill, following her death in a tragic accident there in 1861. Watson's Mill is Manotick's most recognized landmark. Its image is used as a symbol for the village.
Green's Windmill is a restored and working 19th-century tower windmill in Sneinton, Nottingham. Built in the early 1800s for the milling of wheat into flour, it remained in use until the 1860s. It was renovated in the 1980s and is now part of a science centre, which together have become a local tourist attraction.
This glossary of mill machinery covers the major pieces of machinery to be found in windmills, watermills and horse mills. It does not cover machinery found in modern factories.
El Molino Viejo, also known as The Old Mill, is a former grist mill in the San Rafael Hills of present-day San Marino, California, United States, and was built in 1816 by Father José María de Zalvidea from the Mission San Gabriel Arcángel. It is the oldest commercial building in Southern California, and was one of the first ten sites in Los Angeles County to be listed on the National Register of Historic Places, receiving the recognition in 1971. The Old Mill has also been designated as a California Historical Landmark.
A ship mill, more commonly known as a boat mill, is a type of watermill. The milling and grinding technology and the drive (waterwheel) are built on a floating platform on this type of mill. Its first recorded use dates back to mid-6th century AD Italy.
Price's Mill, also known as Calliham's (Callaham's) Mill, Stone's Mill, and Park's Mill, is a water-powered gristmill about 2 mi (3 km) east of the town of Parksville on South Carolina Highway 33-138 at Stevens Creek in McCormick County. Its name in the USGS Geographic Names Information System is Prices Mill. It was built in the 1890s and was named to the National Register of Historic Places on November 22, 1972. At this time, it was one of the few remaining water-powered gristmills in South Carolina.
Roller mills are mills that use cylindrical rollers, either in opposing pairs or against flat plates, to crush or grind various materials, such as grain, ore, gravel, plastic, and others. Roller grain mills are an alternative to traditional millstone arrangements in gristmills. Roller mills for rock complement other types of mills, such as ball mills and hammermills, in such industries as the mining and processing of ore and construction aggregate; cement milling; and recycling.
The Newlin Mill Complex, also referred to as The Newlin Grist Mill, is a water-powered gristmill on the west branch of Chester Creek near Concordville, Pennsylvania built in 1704 by Nathaniel and Mary Newlin and operated commercially until 1941. During its three centuries of operation, the mill has been known as the Lower Mill, the Markham Mill, the Seventeen-O-Four Mill and the Concord Flour Mill. In 1958 the mill property was bought by E. Mortimer Newlin, restored and given to the Nicholas Newlin Foundation to use as a historical park. Water power is still used to grind corn meal which is sold on site. The park includes five historical buildings, which were added to the National Register of Historic Places in 1983, and 150 acres (61 ha) of natural woodland.
Carew Tidal Mill, also called the French Mill, is a corn mill in Pembrokeshire, Wales, powered by tidal water. It was built around 1801 just west of Carew Castle, and replaced a much older mill in the same location. The mill pond fills through open flood gates as the tide comes in. The gates are closed at high tide, and the pond drains through sluices under the mill as the tide falls, driving two undershot water wheels. It is the only intact mill of this type in Wales. It was abandoned in 1937, was restored in 1972, and now houses a museum.
Goldsmith's Inlet is a tidal inlet located in the Town of Southold on the North Fork of Long Island, New York in the United States. The Peconic or Goldsmith Inlet Grist Mill had its beginnings in 1836, when plans were first made for its construction.
norse wheel.
