Wheat flour

Wheat flour: the grain, the powder and the names

Wheat flour is wheat grain milled until the kernel is fine enough to hydrate and disperse through food. A kernel has three parts. The bran is the layered outer coat, the germ is the small embryo, and the endosperm is the large starchy store that makes up most of the grain: roughly 2 to 3 per cent germ, 13 to 17 per cent bran and 80 to 85 per cent endosperm. Whole wheat flour mills all of it into the powder. Most white flours represent only about 72 per cent of the original grain, because the dark bran and the germ are sifted away and the endosperm becomes a fluffy white flour. The flour a cook calls “wheat flour” is therefore a family of products, from a coarse whole meal to a very fine white starch-and-protein powder.

National definitions draw the line in different places. Indian standards define wheat flour, atta, as the product of milling or grinding clean wheat with nothing taken out, and maida as refined wheat flour from which the bran and germ are essentially removed. A third product, “resultant atta,” is made by blending fractions in roller mills after semolina or maida has been separated. In the United States, refined flour is enriched with iron and the vitamins thiamin, niacin and riboflavin, and most enriched wheat flours must also carry folic acid. The word that follows “flour” on a bag, such as bread, cake, all-purpose, whole wheat or atta, says more about its use than the word “wheat.”

In Georgian the word is ფქვილი (pkvili), “flour” in general; wheat flour is ხორბლის ფქვილი (khorblis pkvili), from ხორბალი (khorbali), wheat. In Meskheti, in the southwest of the country, cooks call wheat doli (დოლი) and wheat bread dolis puri (დოლის პური), and they use flour that has been sifted through a wooden sieving box and, for pastry, through a fine sieve.

Where wheat comes from

Flour began as a way of eating wild grass seed. Wild einkorn went into the oldest known bread-like products, baked by hunter-gatherers in what is now Jordan about four thousand years before agriculture began. Einkorn, Triticum monococcum, was then the first wheat to be domesticated, around 10,000 years ago in the Fertile Crescent; the genetics of wild and domesticated populations point to the Karacadağ mountains of southeastern Turkey as the place. From there cultivated crops spread along two main routes, west into central Turkey and later Europe, and east into Transcaucasia, the region that holds present-day Georgia.

Georgia sits in the West Asian region that the botanist Nikolai Vavilov named a centre of origin of cultivated plants, a major area of domestication for wheat, barley, pea, lentil and grape. A national plant-genetic-resources report records 14 cultivated wheat species in Georgia, four of them endemic: Triticum makha, T. timopheevii, T. zhukovski and T. georgicum. Farmers grew landraces of bread wheat with names such as dolis puri, khoulugo, ipqli and rachula, and the Georgian wheats have been used in breeding as a source of resistance to disease and drought; T. timopheevii, for example, is a known source of resistance to scab and rusts. During the twentieth century breeders’ varieties replaced the old ones, and the old landraces survive mostly in collections. Wheat covered between 75,000 and 200,000 hectares in the decade before the report, and winter wheat is a main dryland crop of eastern Georgia. About 95 per cent of the wheat grown worldwide is hexaploid bread wheat, Triticum aestivum, which supplies most of the world’s flour; most of the rest is tetraploid durum wheat, T. durum, milled mainly for pasta.

From quern to roller mill

The first flour was made by hand. A saddle quern was a flat or dished stone with a smaller stone rubbed back and forth across it, usually by a woman kneeling behind it, and it was the main grinding tool for thousands of years. Rotary querns, two round stones with grain fed through a central eye and the top stone turned by a handle, appeared by the fifth century BC in Catalonia, where the earliest dated examples come from, and reached Britain around 400 BC. By the third century BC, animal-driven hourglass mills stood in bakeries across the central Mediterranean, and in about 25 BC the Roman writer Vitruvius gave the earliest written description of a corn mill turned by a vertical waterwheel through gears. At Barbegal near Arles, in the second century AD, two rows of eight mills stepped down a hillside.

Milling was also a source of power and money. The Domesday Book of 1086 recorded more than 6,000 mills in England, and by the early fourteenth century there were an estimated 10,000 water and wind mills. Lords claimed “suit of mill,” the right to have all the corn grown on their manor ground at their own mill, and enforced it, at times by confiscating tenants’ handmills. The miller’s payment, the multure, was taken in kind from each person’s grain, in practice anywhere from one thirtieth to one tenth. The flour of that world was whatever the stones and the sieves of the day produced.

Roller milling changed what flour was. Dedicated roller mills built in Hungary and Switzerland in the 1820s failed, and success came after Abraham Ganz introduced chilled cast-iron rolls in Hungary in 1870, with grooved rolls to break the grain and smooth rolls to reduce it. Britain’s first complete roller mill, the Albert Mills in Liverpool, converted in 1870. The driving forces were a growing taste for white bread and imports of hard wheat from North America, Russia, Australia and India, which gave a higher-gluten flour that the gradual reduction process handled well. By an 1887 survey of the United Kingdom, only 461 of 8,814 mills were complete roller mills, yet they made 65 per cent of the country’s flour. The pale, uniform flour that resulted was easier to chew, to digest and to keep without refrigeration than whole meal, because the bran and germ and their oils were gone.

What the starch and protein do

Wheat flour is mainly starch with a smaller share of protein, and the two behave differently as water and heat arrive. Starch granules absorb water and swell when a flour-and-water mixture is heated. In a laboratory test on a wheat-flour suspension, the ordered structure of the starch was largely disrupted at 70 °C and the starch was fully gelatinized at 80 °C. The swollen starch thickens the liquid, and on cooling it can set into a gel. That is why a spoonful of flour stirred into a hot liquid, as in the Georgian soups below, turns it from thin to spoonable.

The protein behaves another way. Two families of wheat proteins, the gliadins and glutenins, form gluten when flour is hydrated and worked, an elastic and stretchy network that traps gas in dough. In the same laboratory test, soluble protein aggregated into insoluble polymers above 70 °C, mainly through disulfide bonds, so heat sets the protein as well. In bread dough, kneading develops that network; in the stirred pastes and soups below, nobody is trying to.

Flour also carries enzymes. Cereal flours contain amylases, which break damaged or gelatinized starch into dextrins and the sugar maltose. In dough those sugars feed yeast, raising gas production and improving crust color and flavor. Wheat flour is therefore both a structure and a food for fermentation: its own enzymes supply the sugar a culture works on.

Flour in a Georgian kitchen

The Meskhetian kitchen shows how many jobs one flour can do. Bread there is raised without bought yeast. Cooks keep a bread mother: while kneading, they set aside a fistful of dough, store it salted in a clay pot for a week so that it sours and acquires the ability to rise, then take it out the day before baking, knead it in a small trough and leave it overnight in a warm place. In the morning they add flour and work the dough to the size they want. The loaves named include lavash, shoti, kokora (a bread with a hole in the middle), long lavash and the round somini. Bazlama is baked on an iron saj, a large round griddle that is heated until a sprinkling of flour on it does not burn, and ukha is a thin flatbread made quickly without leavening. Kada, a layered pastry brushed with melted lard, was once baked on feast days such as Easter and weddings, and its flour is first sifted through a fine sieve.

Flour is also a thickener. Hasuta is made by heating clarified butter and bakmaz, boiled-down mulberry juice, together in a wide pan and stirring flour in slowly with a wooden spoon until the mixture thickens to a porridge-like paste, which is worked a little longer so that it loses its raw-flour taste and eaten with bread. Jifu’a is wheat flour stirred into boiling water and milk to a thin porridge. A tart soup is made by tearing dried tklapi into small pieces, softening them in cold water, adding them to boiling salted water and thickening the pot with two or three spoonfuls of flour, then adding clarified butter, onion and garlic. A nettle soup is thickened with flour stirred into a cup of its own broth, with a beaten egg added. In each, the cook is using the same property: flour dispersed in liquid and heated thickens it.

The Meskhetian tklapi shows the method at scale. Four to five buckets of cooked mulberries are pressed and strained for juice. While the juice boils, up to 4 kg of flour is stirred into a bucket of juice, thinned until it passes a strainer, and cooked at low heat with constant stirring. The grain of this flour is not named. A Georgian recipe uses wheat flour: mulberries are chopped finely, sieved and boiled to one-tenth of their volume, a thick paste of wheat flour and water is made in a separate pan and added at 0.5 kg of flour to three litres of fruit, and the dense mixture is spread over linen and dried in the sun for about a day. When the surface is lightly dampened, the sheet lifts off, is rolled up, and keeps at room temperature for a long time. The same chapter notes that tklapi can also be made without flour. Flour in tklapi is therefore an option, not a requirement.

Choosing, storing and using it safely

Choose flour for its job. A recipe that says only “flour” leaves the choice of refined or whole, strong or soft, to the cook, and the difference is real: whole wheat flour keeps the bran and germ with their fiber, oils and nutrients, while refined flour has lost them. Keep flour in an airtight container in a cool, dry place with humidity below 60 per cent; refrigerating or freezing extends the life of whole wheat flour, which holds the oil-rich germ, and the package date is the guide for the rest.

Flour is a raw agricultural product. It comes from grain grown in fields, which can carry Salmonella and pathogenic Escherichia coli, and milling does not kill them. Raw flour, dough and batter should never be tasted, flour should be kept apart from ready-to-eat food because it spreads easily, hands and surfaces should be washed after handling it, and home heat-treatment of flour is not advised because it may not kill every bacterium. Baking, boiling or frying the finished food is what makes it safe. That includes the thickened soups, porridges and fruit sheets above: flour added to boiling liquid is cooked, but a sun-dried sheet is not a safety step.

Wheat is one of the nine major food allergens under U.S. labeling rules, and wheat flour contains gluten. Celiac disease, in which gluten damages the small intestine, is treated with a strict gluten-free diet, and wheat allergy is a separate immune reaction that does not cause that long-term damage. Neither condition can be managed by choosing a different grade of wheat flour.

What the sources do not give

Neither Georgian account names the wheat class, protein level, extraction or mill behind its flour, and the Meskhetian tklapi passage does not say whether its flour was wheat. No source gives a flour-to-fruit ratio that can be scaled for the Meskhetian bucket method, because the bucket size is not stated.