Wheat flour
Encyclopedia
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
used for human consumption. More wheat flour is produced than any other flour. Wheat varieties are called "clean," "white," or "brown" if they have high gluten content, and they are called "soft" or "weak" flour if gluten
Gluten
Gluten is a protein composite found in foods processed from wheat and related grain species, including barley and rye...
content is low. Hard flour, or bread flour, is high in gluten, with 12% to 14% gluten content, and has elastic toughness that holds its shape well once baked. Soft flour is comparatively low in gluten and so results in a finer or crumbly texture. Soft flour is usually divided into cake flour, which is the lowest in gluten, and pastry flour, which has slightly more gluten than cake flour.
In terms of the parts of the grain (the grass fruit
Caryopsis
In botany, a caryopsis is a type of simple dry fruit — one that is monocarpelate and indehiscent and resembles an achene, except that in a caryopsis the pericarp is fused with the thin seed coat....
) used in flour—the endosperm or protein/starchy part, the germ or protein/vitamin-rich part, and the bran or fibre part—there are three general types of flour. White flour is made from the endosperm only. Whole grain
Whole grain
Whole grains are cereal grains that contain cereal germ, endosperm, and bran, in contrast to refined grains, which retain only the endosperm. Whole grains can generally be sprouted while refined grains generally will not sprout. Whole-meal products are made by grinding whole grains in order to make...
or wholemeal flour is made from the entire grain, including bran
Bran
Bran is the hard outer layer of grain and consists of combined aleurone and pericarp. Along with germ, it is an integral part of whole grains, and is often produced as a by-product of milling in the production of refined grains. When bran is removed from grains, the grains lose a portion of their...
, endosperm
Endosperm
Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...
, and germ
Cereal germ
The germ of a cereal is the reproductive part that germinates to grow into a plant; it is the embryo of the seed. Along with bran, germ is often a by-product of the milling that produces refined grain products. Cereal grains and their components, such as wheat germ, rice bran, and maize may be used...
. A germ flour is made from the endosperm and germ, excluding the bran.
Types
- All-purpose or plain flour is a blended wheat flour with a protein content lower than bread flour, ranging between 9% and 12%. Depending on brand or the region where it is purchased it may be composed of all hard or soft wheats, but is usually a blend of the two, and can range from low protein content to moderately high. It is marketed as an inexpensive alternative to bakers' flours which is acceptable for most household baking needs.
- Bleached flour is a white flour treated with flour bleaching agentFlour bleaching agentFlour bleaching agent is a food additive added to flour in order to make it appear whiter and to oxidize the surfaces of the flour grains and help with developing of gluten.Usual bleaching agents are:...
s to whiten it (freshly milled flour is yellowish) and to give it more glutenGlutenGluten is a protein composite found in foods processed from wheat and related grain species, including barley and rye...
-producing potential. Oxidizing agents are usually employed, most commonly organic peroxideOrganic peroxideOrganic peroxides are organic compounds containing the peroxide functional group . If the R' is hydrogen, the compound is called an organic hydroperoxide. Peresters have general structure RCOOR. The O-O bond easily breaks and forms free radicals of the form RO·...
s like acetone peroxideAcetone peroxideAcetone peroxide is an organic peroxide and a primary high explosive. It takes the form of a white crystalline powder with a distinctive bleach-like odor....
or benzoyl peroxideBenzoyl peroxideBenzoyl peroxide is an organic compound in the peroxide family. It consists of two benzoyl groups bridged by a peroxide link. Its structural formula is [C6H5C]2O2. It is one of the most important organic peroxides in terms of applications and the scale of its production...
, nitrogen dioxideNitrogen dioxideNitrogen dioxide is the chemical compound with the formula it is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odor and is a prominent...
, or chlorineChlorineChlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
. A similar effect can be achieved by letting the flour oxidize with oxygen in the air ("natural aging") for approximately 10 days; however, this process is more expensive due to the time required. Flour bleached with benzoyl peroxideBenzoyl peroxideBenzoyl peroxide is an organic compound in the peroxide family. It consists of two benzoyl groups bridged by a peroxide link. Its structural formula is [C6H5C]2O2. It is one of the most important organic peroxides in terms of applications and the scale of its production...
has been prohibited in the UK since 1997. - Bread flour or strong flour is always made from hard wheat, usually hard spring wheat. It has a very high protein content, between 10% and 13%, making it excellent for yeast bread baking. It can be white or whole wheat or in between.
- Bromated flour has a maturing agent added. The agent's role is to help with developing glutenGlutenGluten is a protein composite found in foods processed from wheat and related grain species, including barley and rye...
, a role similar to the flour bleaching agentFlour bleaching agentFlour bleaching agent is a food additive added to flour in order to make it appear whiter and to oxidize the surfaces of the flour grains and help with developing of gluten.Usual bleaching agents are:...
s. BromateBromateThe bromate anion, BrO, is a bromine-based oxoanion. A bromate is a chemical compound that contains this ion. Examples of bromates include sodium bromate, , and potassium bromate, .Bromates are formed many different ways in municipal drinking water...
is usually used. Other choices are phosphatePhosphateA phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
s, ascorbic acidAscorbic acidAscorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form of vitamin C. The name is derived from a- and scorbutus , the...
, and malted barleyBarleyBarley is a major cereal grain, a member of the grass family. It serves as a major animal fodder, as a base malt for beer and certain distilled beverages, and as a component of various health foods...
. Bromated flour has been banned in much of the world, as bromateBromateThe bromate anion, BrO, is a bromine-based oxoanion. A bromate is a chemical compound that contains this ion. Examples of bromates include sodium bromate, , and potassium bromate, .Bromates are formed many different ways in municipal drinking water...
is classified as possibly carcinogenCarcinogenA carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
ic in humans (Group 2B) by the International Agency for Research on CancerInternational Agency for Research on CancerThe International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....
(IARC), but remains available in the United States. - Cake flour is a finely milled white flour made from soft wheat. It has very low protein content, between 8% and 10%, making it suitable for soft-textured cakeCakeCake is a form of bread or bread-like food. In its modern forms, it is typically a sweet and enriched baked dessert. In its oldest forms, cakes were normally fried breads or cheesecakes, and normally had a disk shape...
s and cookieCookieIn the United States and Canada, a cookie is a small, flat, baked treat, usually containing fat, flour, eggs and sugar. In most English-speaking countries outside North America, the most common word for this is biscuit; in many regions both terms are used, while in others the two words have...
s. The higher protein content of other flours would make the cakes tough. Highly sifted cake flours may require different volume amounts in recipes than all-purpose flour. Using the scoop and level method, well-sifted flour usually produces 125g per cup. However, most American recipes are written with 140 grams of flour per cup, so weighing and experimentation can be helpful in baking unfamiliar recipes. Small weight differences can greatly affect the texture. American Cake flour is bleached; in countries where bleached flour is prohibited, plain flour can be treated in a domestic microwave to improve the texture of the end product. Related to cake flour are masa harinaMasaMasa is Spanish for dough. In the Americas it is often short for masa de maíz, a maize dough made from freshly prepared hominy. It is used for making corn tortillas, tamales, pupusas, arepas and many other Latin American dishes. The dried and powdered form is called masa harina, masa de harina,...
(from maizeMaizeMaize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
), maida flourMaida flourMaida is a finely milled and refined flour of wheat, closely resembling cake flour, and used extensively in making Indian fast food and Indian bakery products such as pastries and breadand sometimes in making traditional Indian breads such as paratha and naan. It is made from the endosperm of the...
(from wheat or tapiocaTapiocaTapioca is a starch extracted Manihot esculenta. This species, native to the Amazon, Brazil, Colombia, Venezuela, Cuba, Puerto Rico, Haiti, the Dominican Republic, Honduras, and most of the West Indies, is now cultivated worldwide and has many names, including cassava, manioc, aipim,...
), and pure starchStarchStarch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
es. - Graham flourGraham flourGraham flour is a type of whole wheat flour named after the American Presbyterian minister Rev. Sylvester Graham , an early advocate for dietary reform...
is a special type of whole wheat flourWhole wheat flourWhole wheat flour is a powdery substance derived by grinding or mashing the wheat's whole grain. It is used in baking but typically added to other "white" flours to provide nutrients , texture, and body to the finished product....
. The endosperm is finely ground, as in white flour, while the bran and germ are coarsely ground. Graham flour is uncommon outside of the USAUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
and EuropeEuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. It is the basis of true graham crackerGraham crackerThe graham cracker was developed in 1829 in Bound Brook, New Jersey, by Presbyterian minister Rev. Sylvester Graham. The true graham cracker is made with graham flour, a combination of fine-ground white flour and coarse-ground wheat bran and germ. Graham crackers are often used for making s'mores...
s. Many graham crackers on the market are actually imitation grahams because they do not contain graham flour or even whole-wheat flour. - Instant flour is pregelatinized (precooked) for easier incorporation in gravies and sauces.
- Pastry flour or cookie flour or cracker flour has slightly higher protein content than cake flour but lower than all-purpose flour. Its protein content ranges between 9% and 10%. It is available as a white flour, a whole-wheat flour, or a white flour with the germ retained but not the bran. It is suitable for pie pastry and tarts, some cookies, muffins, biscuits and other quick breads. Flour is shaken through a sieveSieveA sieve, or sifter, separates wanted elements from unwanted material using a woven screen such as a mesh or net. However, in cooking, especially with flour, a sifter is used to aerate the substance, among other things. A strainer is a type of sieve typically used to separate a solid from a liquid...
to reduce the amount of lumps for cooking pastry. - Self-rising or self-raising flour is white flour that is sold premixed with chemical leavening agents. It was invented by Henry JonesHenry Jones (baker)Henry Jones was a baker in Bristol, England, who was responsible in 1845 for inventing self-raising flour.Jones was born in Monmouth, and established a bakery in Broadmead, Bristol. He was granted a patent for self-raising flour in 1845, and by the end of 1846 its runaway success led to him being...
. Self-rising flour is typically composed of the following ratio: - 1 cup (100 g) flour
- 1 and 1/2 teaspoon (3 g) baking powderBaking powderBaking powder is a dry chemical leavening agent used to increase the volume and lighten the texture of baked goods such as muffins, cakes, scones and American-style biscuits. Baking powder works by releasing carbon dioxide gas into a batter or dough through an acid-base reaction, causing bubbles in...
- a pinch to ½ teaspoon (1 g or less) saltSaltIn chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
- Sharp flourSharp (flour)Sharp flour is made from hard wheat. It is a term used by millers in Fiji and is in common usage throughout the populace as evidenced by newspaper reports whenever the price of flour changes, with the new price of sharp listed. Sharp is used as an ingredient for roti in Fiji.-External links:**...
is produced in Fiji and primarily used in Indian cuisine. - SpeltSpeltSpelt is a hexaploid species of wheat. Spelt was an important staple in parts of Europe from the Bronze Age to medieval times; it now survives as a relict crop in Central Europe and northern Spain and has found a new market as a health food. Spelt is sometimes considered a subspecies of the...
flour is a flour produced from the type of wheat called spelt. It is less commonly used in modern cooking than other wheat varieties. It is still used for speciality baking. - Tang flour or wheat starch is a type of wheat flour used primarily in Chinese cookingChinese cuisineChinese cuisine is any of several styles originating in the regions of China, some of which have become highly popular in other parts of the world – from Asia to the Americas, Australia, Western Europe and Southern Africa...
for making the outer layer of dumplingDumplingDumplings are cooked balls of dough. They are based on flour, potatoes or bread, and may include meat, fish, vegetables, or sweets. They may be cooked by boiling, steaming, simmering, frying, or baking. They may have a filling, or there may be other ingredients mixed into the dough. Dumplings may...
s and buns. It is also used in Vietnamese cuisine, where it is called bột lọc trong.
External links
- http://www.namamillers.org/ci_products_wheat_mill.html