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Flour Bolting (Sifting) and Bolting Cloth.

Flour Bolting (Sifting) and Bolting Cloth,
Theodore R. Hazen.

During the period of the 16th to the 19th centuries a lot of developments happened in sifting or bolting flour. The fabric and the machines of bolting changed during this period. Some people seem to thing that sifting or bolting flour is something of the modern era. The Romans sifted wheat into seven grades of flour, and for the most part used woven horse hair for bolting cloth.

What factors effected how ground grain was sifted or bolted? (1) The miller ability to clean grains. (2) How grain was milled. (3) The materials available in a certain time period which could be used to sift ground flour or chop.

The reason that you can sift or bolt flour is because when the millstones grind something, it does not grind it all to the same texture and size. Different parts of the grain come off or apart in different sizes. It is a muddled mass of different size particles. If a grain could be ground to particles of all of the same size, there would be no need for sifting. Because you can bolt flour means you can sift out the desired parts and discard the mediocre, or second rate.

What does sifting do? It freshest up the flour. It lightens it, and makes it more lively. In this process it improves the baking qualities of the flour. It increases its volume, because it has settled in the bin or sack.

So I guess, we need to start with the 1600's. Bolting was not spelled "bolting." The spelling in the 1600's is "boulting." As in "boulting flour," "boulter," and "boulting mill." Yes, a "boulting mill." A "boulting mill," is a separate building, often far remove from the mill where it was ground. In some cases, flour was "boulted" by the baker, who would charge a separate charge or toll for sifting the flour. Proof of this is that "Boulter," and "Boulting" along with "Bolter" is a person's last name. So the miller would take his toll for grinding the grain, the boulter would take his toll for sifting the flour, and the baker would take his toll for baking the flour. This meant to get from a sack of grain to a loaf of bread, you would have three tolls taken. One for milling the grain, another for sifting or boulting it, and a third for baking it into bread. They took their toll from the good stuff, and the part left behind belonged to the customer. Originally a "boulter," was a person, like the miller and the baker. The "boulter," was the person who sifted the flour by hand. The French considered the sifting of flour such a complicated process which could not be done in the same building as the grain was ground. Hence, the need for a separate structure to house the devices used in sifting the flour. Bakers for a very long period preferred to do their own sifting

During the period of the 1600's to the 1900's, the bolting or sifting surfaces changed and evolved. There were three basic beginning of bolting or sifting in the 1600's. (1) The basic method of sifting was with a "temse" a round flat sieve. These hand operated sifters were made from two to three feet in diameter. A miller would use them to sift material from one bin to another. They could be used to sift ground meal or chop from a sack into a box, pail or tub placed on a table. A sifting operation would have a series of different "temse" with various mesh openings to sift out fine to course materials. They would start with the finest mesh and sift out the finest flour first, and the material not passing though that mesh openings would be sifted though a larger mesh screen on another "temse." (2) Another method of sifting or bolting flour was called, "flogging." You collect the flour as it comes down from the chute from the millstones into a sack. The sack would only be allowed to become partly filled. The sack would be "flogged," or beaten against a table surface. The finer flour would be "flogged," though the mesh of the weave of the sack, and the courser particles would remain in the sack so they could be discarded. During the 1600's and 1700's the floor was an acceptable place to store grain and flour. (3) The German method if sifting was "sock" or "tube milling." Rather than a wooden square chute being attached to one side of the millstone cover a long round sock or tube was attached to the millstone cover, and the other end (the collar) was attached to an outside wall of the mill. As the ground material pass from the millstones down the sock, the miller's helper stood in the mill basement hitting the sock with a stick. The flour would come though the weave of the sock, and the courser material would remain inside of the sock to be deposited in the mill stream outside of the mill. During the 1800's an eccentric was used to shake the sock with a stick so the miller's helper would be eliminated and the system be some what automatic. (4) Another system used on the European Continent was a slanting flat mesh screen (of either single mesh or several mesh openings) which was hand-agitated by the miller's helper, or the boulter. The ground flour was collected in a sack and dumped into a hopper at the head of the device, and from the bottom the ground material was gradually fed onto a moving flat screen. The hand-agitation was accomplished by a hand-crank.

Boulting cloth was an extremely, hard material of even weave, originally of linen or cotton, and from the end of the 18th century silk mesh which was as fine as one hundred treads to the inch. Agitation of the boulter screen would the finer particles of flour to though the cloth, which over tailed the courser materials. The problem with using linen or cotton, the ground material would give it rough treatment, and would soon wear out. So they looked for a stronger material. About the time the Pilgrims were struggling to build Plymouth Plantation, patents were issued in Great Britain for the making of woven wire cloth. Then about 100 years later, a Scot named John Milne, invented a sifting reel that rotated instead of being shaken. Even though this was a great breakthrough, at first the reel was hand-cranked, or rotated by hand. The ground material would be poured into a hopper at the head of the reel where it gradually feed into the revolving reel. These reels could be 12 to 14 feet in length, and the over tails were discarded out of the mill. In the end of the century the reels were mill powered by cogs, and then later by flat leather belting which greatly improved the constantly of the flour sifted though the screens by wooden chutes rather than feed hoppers.

The problem with wire cloth screens is the nature of the wire. You can only make wire of small enough diameter to make so fine of a mesh screen. The reel made it possible for silken gauze from the East Indies to be used as a favored material. The Dutch weavers in Haarlem began using a stronger cloth silk during the 1700's. Bolting cloth came in two weaves. Regular weave for interior cloth and very fine mesh, and twisted weave which prevented the mesh from spreading. The twisted weave could be made by the Dutch weavers at 88 openings per inch, and the regular weave could be made to 125 or more openings per inch. Bolting cloth was made from wool, linen, cotton, horsehair, and even silk cloth. The problems with fabrics was moisture. Air caused it to become taut, and the lack of moisture caused it to grow too slack. The problem was overcome when inventors produced an artificial silk, nylon. Nylon maintained its tautness with little change, and it laster three times longer than natural silk. Since it was invented, almost all sifting cloth was made exclusively from this artificial fiber.

It was not until the middle to late 1700's did millers have a means of cleaning grain. This meant that they could not remove dirt, seeds, fungus, smut, straw, sticks, mold, insects, manure, and animal droppings. Before this time, millers used sifting, or the boulting of flour to also clean it. Well dirt is brown, and the brown parts of wheat, rye, barley, and oats cause flour to spoil. The bran is a flake which absorbs moisture, and will case the flour to spoil or mildew. Germ is naturally oily, and causes the flour to turn rancid. Bugs and rodents are not stupid, they know which is the best part of the grain. I knew someone who worked in a big merchant flour mill in Buffalo, New York. One time I asked him what to they do to control rats and mice. He answered, "Nothing! We let them eat all of the white flour that they want, and we find them with their little stomachs blotted out, dead of malnutrition."

The bread of a country or region is effected by the millstones that are available for that area. The English Peak millstones used in England, and the German Cullin millstones, which are used by the Dutch and German millers, is a naturally a soft stone. So the cutting edges (closeup) are broken, and then tend to break up the bran into small particles which is difficult to sift out or remove. The native bread of these areas tends to be brown. The French use French millstones which are much harder material of fresh water quartz. The cutting edges (closeup) are sharp, and tend to scrap off the bran in large broad flakes which is makes it easy to sift out and remove. The French gave up using rye because of the fungus ergot, which not removed from the grain (when the fungus matures it turns from a purple to the same color as the rye kernels. It is also the same size and shape as the rye), milled, and baked into bread has the same chemical composition as LSD. Let the crazy Germans eat their rye, and pumpernickel bread. So white wheat bread was safer to eat which became known as French bread. The United States was the largest importer of French millstones, and it was America which supplied the flour for the Napoleonic Wars.

In England, the flour is called "Whole Meal." "Whole Wheat Flour" this is a creation of the 20th century, it is not "Whole" by law, the bran has to be sifted out or removed. The law states that when it started the milling process the grain was "whole." This is like corn meal today which is sold basically bolted and unbolted, but if you just pick up a sack chances are it has the bran sifted out. The only difference is that they do not sell real course ground unbolted "whole wheat flour" which is actually "graham flour."

Soft wheat has a larger percentage of white endosperm, and less gluten which make bread rise. So soft wheat makes a better cake and pastry flour than a bread flour. Hard wheat flour was not introduced to America until the 1860's from the Ukraine. Hard wheat was considered an inferior wheat which contained very little white endosperm, and a great deal of gluten. So it makes a better bread flour. The roller milling system and machines developed for that system turned the hard wheat from an inferior wheat to a superior white flour.

When you mill a 100 pounds of soft or English wheat. You get about 72 percent or pounds of white flour, and about 4 pounds of bran, the rest is middlings. The bran and middlings were considered offals, and tossed into the creek. Early millers were adding to the eutrophication of mill streams by dumping their offals into the water. An early Native American Indian Chief gave his name to middlings or ship's stuff. It is called, "Red Dog," because of the New England miller who made a deal with the Indians who promised to take all of the middlings the mill could produce. Ship's stuff is the name give to the grade of flour which was made into ship's biscuit. It was made from the part of the wheat which would absorbs moisture easily, and would be prone to meal worms. There are some people who simply say, "if the bugs won't eat it, maybe I should not be eating it. Read a copy of William Dufty's book, "Sugar Blues Exposing Sugar, the killer in your diet - offering you a life-saving, sugar-free way to health. " There was not an animal feed industry or business until after the American Civil War.

White flour had an export value. It has a longer self life than the brown parts of the grain. The bran absorbed moisture and caused the flour to spoil or mildew. The germ caused the flour to turn rancid. There was white flour, and brown flour which was called "dog flour" because most of the time it was not fit to feed dogs.

What gives flour its different taste from one region or area of the country is basically dirt. The grain cleaning process cannot remove all of the dirt attached to, or embedded in the grain. This means that corn grown, and mill in Pennsylvania, tastes different than grain grown in Ohio, or even the Eastern shore of Maryland. If you read the book, "The Medal of Gold A Story of Industrial Achievement," by William C. Edgar, The Bellman Co., Minneapolis, 1925, it is about the flour milling industry in Minneapolis, when they began making Minneapolis style white flour. The American housewife just would not use it because the milling process removed all of the taste, and flavor from the flour. So they started added street sweepings from Minneapolis as an additive to give it taste, and so people would use it.

Ellen and Vrest Orton's book, "Cooking with Whole Grains," states that stone ground flour is not only more nutritious, but it is infinitely more flavorful. "Must of our national illness is caused by crazes for food that is (1) white, (2) refined, (3) keepable. All these crazes are exemplified in white flour. The best food chemist are the earth and the sun, which produce the whole wheat that the steel rollers of the white flour millers spoil. White flour makes white is stuff to be eaten fresh, not to be "kept" as if it were an heirloom......Wholemeal flour naturally does not "keep" because the germ in it is alive. Germless white flour "keeps." This is found in the chapter called "Mysteries of the Mill."

Read the Following Web Page: Additives (preservatives) in Flour.

Second floor large multiple reel flour bolting machine, Mingus Flour Mill


The history of flour sifting from the 1600's to the 1900's when though various stages in the development of flour sifters. (1) First they used flat screens. (2) About 1730 the began to use round reels or cylinders to sift the flour. (3) Then about 1870 to the 1880's they began using flat screens once again in a machine called a "plansifter."

Screen size or mesh has changed its method of identification. So I will give the sizes in opening per linear inch each way in a square or right angle. When grain is mill they would run it over the finest screen first, to finally the largest mesh openings.

During the period of the 1700's and 1800's the finest most mills had was about 120 openings per linear inch. Cake and pastry flour could be sifted though 64 openings per linear inch. Up until the American Civil War most millers had used only soft or English wheat which contains more white endosperm, and less gluten which makes bread rise. So then it makes a better cake and pastry flour than a bread flour. Basic white flour or unbleached white flour is sifted though a mesh of 32 openings per linear inch. Wheat middlings or wheat cereal is sifted though a mesh of 16 to 18 openings per linear inch. Wheat bran is tailed over the screen because it cannot pass though the openings. This size 16 to 18 inch mesh per linear inch is also about the same as the mesh of standard window screen.

Buckwheat and corn (maze) has no explosive dust. Buckwheat is very dusty when it is milled. Wheat, barley, barley, and oats contain explosive dust. The dust is more explosive than gunpowder, and 35 times more explosive than coal dust. World War One spy school would teach you how to level any structure (or building) with a bean can full of flour, and a tuna fish can of gasoline. Rye is very dust (like buckwheat) when it is milled, and unlike buckwheat wheat which is an herb and not a cereal grain, rye contains explosive dust, and sometimes the fungus ergot.

Oliver Evans' devices (5), and his automated flour milling system brought the flour mill, and the boulting (bolting) mill back together under one roof. It made it possible to conduct the processes of cleaning grain, milling it, cooling it, sifting it, and then packing it into flour barrels with using a fraction of the labor, and the time once involved. The torn bolting screens would have been replaced by the baker, the bolter, and the miller. In large merchant millstone mills, and the later roller mills, one of the many specialized employees is a person called, the "screener." He is the person who maintains all of the bolting surfaces in the mill. The plansifter holds a series of flat removable screens, so the "screener," and his helper simply pull out the torn screen, and replace it with new panels. The most important piece of machinery in a pre-Oliver Evans mill is the sack hoist, and after Evans it all changed.

The main problem with "The Young Mill-Wright and Miller's Guide," by Oliver Evans, first edition, was that it was basically out-of-date when it was first published. "The Practical Mill-Wright," by Thomas Ellicott was the state-of-the-art of millwrighting when Evans invented his improvements, but these devices needed a more suffocated system which could adequately power the additional machinery beyond just the mill's millstones. It should have been more clearly stated that Ellicott's section was how mills were laid out before Oliver Evans' inventions, and was therefore made outdated. Thus, there is this great myth that the Thomas Ellicott section represents an Oliver Evans mill. This is just not correct! During its various editions, hybrid water wheels were developed, and no book really addressed their construction and design. The science of mechanical transfer of power quickly changed from cog driven to flat leather belting. The main downfall of Evans' book is it does not really tell anyone how to make the machinery work that he invented. This is why many mills which had Oliver Evans automated flour making machinery, installed it just the way it was shown in the plates in his book.

The flour milling and millwright books that appeared after Oliver Evans never really addressed how mills were laid out, and machinery was operated. During the later reprint editions of "The Young Mill-Wright and Miller's Guide," the modern water turbine was developed in France which made the vertical water wheel obsolete. Even the various water turbine catalogs which sold mill owners on their wheels never showed how machinery could be operated from their wheels. The Fitz Water Wheel Company which kept alive the romance of the vertical water wheel for one hundred years after it became obsolete, really did not really show how machinery could be powered by their vertical metal water wheels.

No two mills were exactly alike. They are as different as finger prints. Even mills built by the same person, or millwright, the amounts of fall and water where different from one mill site (or seat) to another, and the products made by the mill was different. When they are gone, they are gone. It is like trying to recreate a dead person's fingerprints who was never fingerprinted during their lifetime.

Oliver Evans needed to revise "The Guide" for its two reprint editions that occurred during his lifetime. It was the basic problem with any artist, or inventor, he had simply moved on to other things. The fifth edition was then published in 1826. This edition saw the book completely reset with new copper plates engraved. On June 15, 1826 Oliver Evans' son Cadwallerader Evans added to the book's appendix, this included metal gearing, the flour press and iron hubs for water wheels. The book that Oliver Evans worked on so long was then fiddled with by Thomas P. Jones the editor of the Franklin Institute publication the Journal. Many of the original essays were shortened or eliminated, and dozens were rewritten, sadly nothing was none to clarify any of the concepts presented in the original work. To the appendix was added the work of Robertson Buchanan, with his "Practical Essays on "Mill-work and other Machinery," including information on reaction water wheels. The only an impressive statement added to the 1826 edition was: "Fifth Edition, with Additions and Corrections by Thomas P. Jones, Member of the American Philosophical Society, Correspondent of the Polytechnic Society of Paris, Editor of the Journal of the Franklin Institute of the State of Pennsylvania, and late Professor of Mechanics in that Institution." Jones added several excerpts from the Franklin Institute Journal , but retained parts of Oliver Evans original appendix. All of the plates were moved to the back of the book, rather than being with part four "The Young Miller's Guide" section and the other plates being with part five "The Practical Mill-wright" section, this only added further confusion to understanding the work. It has been said over and over again, I can't make sense of Oliver Evans' book. The reality of it, they need some prior understanding on milling technology before they can sit down and understand "The Young Mill-Wright and Miller's Guide." Oliver Evans was correct in his concepts, the problem is our understanding of his work. As to Mr. Jones, he obliviously never heard perhaps our old saying, "if it works, don't mess with it!"

See: Flour & Meal Products from Historic Mills.

To make simple flat screen sifters make a wooden frame about 12 to 18 inches square. Use a staple gun to staple the screen to the bottom of the sifter frame. Then cover the end surface with the stapled screen with wooden molding. Remember when you order mesh screen you have to tell them how many openings you want per linear inch, and what material you want. It can be steel, stainless steel, brass, silk, and nylon.

Bolter screen:

1. H.R. Williams Mill Supply Inc., 4221 N.E. 34th Street, Kansas City, MO, 64117 U.S.A. PH: 816/452-1520, 800/283-8182; FAX: 816/452-2183
CONTACT: Scott Jordan, Sales & Mktg. Mgr. Product Description: Bolting screen; wire (brass, steel, stainless steel), silk, nylon; custom cut and made to order with solder joints and webbing.

2. Howes, S., Co., Inc. 25 Howard St., Silver Creek, NY 14136 USA, Tel: 888-255-2611, Fax: 716-934-2081 Product Description: Custom & Standard Screening & Sifting -Capabilities Include Complete Metal Fabrication, Replacement Parts, Spare Parts, Oscillating Drives,Screen Perforating.

3. Great Western Mfg. Co., Inc., 2017 S. 4th St., Leavenworth, KS 66048 0149 USA Tel: 913-682-2291, Fax: 913-682-1431 Product Description: Sifting, Screening, Flour Mill & Grain Elevator Machinery & Supplies.

4. Buhler Inc., 1100 Xenium Lane, P.O. Box 9497, Minneapolis, MN, 55440 U.S.A. PH: 612/545-1401; FAX: 612/540-8533 Product Description: Sifting, Screening, Flour Mill & Grain Elevator Machinery & Supplies.

Books about Bread:

1. Bread of Dreams: Food & Fantasy in Early Modern Europe (ISBN:0745603491)
Piero Camporesi, Translated by David Gentilcore, Cambridge: Polity Press, Oxford, 1989, University of Chicago Press, 1996.

Piero Camporesi is one of the most original & exciting cultural historians in Europe today. In this remarkable book he examines the imaginative world of poor & ordinary people in pre-industrial Europe, exploring their everyday preoccupations, fears & fantasies. Camporessi develops the startling claim that many people in early modern Europe lived in a state of almost permanent hallucination, drugged by their hunger or by bread adulterated with hallucinogenic herbs. The use of opiate products, administered even to infants & children, was widespread & was linked to a popular mythology in which herbalists & exorcists were important cultural figures. Through a careful reconstruction of the everyday imaginative life of peasants, beggars & the poor, Camporesi presents a vivid & disconcerting image of early modern Europe as a vast laboratory of dreams. Bread of Dreams is a rich & engaging book which provides fresh insight into the everyday life & attitudes of people in pre-industrial Europe. Camporesi's vision is breathtaking & his work will be much discussed among social & cultural historians. This edition includes a new preface by Roy Porter, Senior Lecturer in the Social History of Medicine at the Wellcome Institute.

2. Treatise on Bread and Bread-Making
Graham, Sylvester, Boston: Light & Stearns, 1836, 1837. Reprinted by Lee Foundation for Nutritional Research, Milwaukee 1, Wisconsin, and St. Catherines, Provoker Press, 1970.

3. Breads, White and Brown: Their Place in Thought and Social History.
McCance, R. A., and E. M. Widdowson, Philadelphia and Montreal: J. B. Lippincott Company, 1956.

McCance argues, "after the turn of the century nothing but a famine could have forced the working classes of south-eastern England to forsake their white bread. It became their 'flag.'" The idea that they were being denied proper food (as some were forced to eat "brown" bread, baked with wheat flour from which the bran has not been removed) enraged the populace. Interestingly, bakers contributed to the public's tastes; during the early part of the century some unprincipled or struggling bakers made the less expensive brown bread inedible so that no one would purchase it. In addition, although "additions" to bread were prohibited in 1758, competition drove many bakers to add alum, chalk, or ammonium to their bread in an effort to produce a whiter loaf. F. Accum publicly denounced this practice in his popular book, A treatise on adulterations of food, and culinary poisons, etc. (1820); however, the actual effects of these practices on the health of the public were minimal.

4. The Englishman's Food: A History of Five Centuries of English Diet.
Drummond, J.C., and A. Wilbraham, London: Jonathan Cape, 1939.

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Copyright 2007 by T. R. Hazen