View source for Flour

{{Short description|Cereal grains ground into powder}}
{{Other uses}}
{{distinguish|Flower}}
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{{Infobox food
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[[File:All-Purpose Flour (4107895947).jpg|thumb|All-purpose flour]]
[[File:Farine de manioc et de mais.jpg|thumb|[[Cassava]] flour (left) and [[maize flour|corn flour]] (right) in [[Kinshasa]], [[Democratic Republic of Congo]]. These flours are basic ingredients for the cuisine of [[Central Africa]].]]
[[File:Soy_powder.jpg|thumb|[[Kinako]]]]

'''Flour''' is a [[powder]] made by [[Mill (grinding)|grinding]] raw [[grain]]s, [[List of root vegetables|roots]], [[bean]]s, [[Nut (fruit)|nuts]], or [[seed]]s. Flours are used to make many different [[food]]s. [[Cereal]] flour, particularly [[wheat flour]], is the main ingredient of [[bread]], which is a [[staple food]] for many cultures. [[Maize flour|Corn flour]] has been important in [[Mesoamerica]]n 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]].

Cereal flour consists either of the [[endosperm]], [[cereal germ|germ]], and [[bran]] together (whole-grain flour) or of the endosperm alone (refined flour). ''Meal'' is either differentiable from flour as having slightly coarser particle size (degree of [[comminution]]) or is synonymous with flour; the word is used both ways.

The [[Centers for Disease Control and Prevention|CDC]] has cautioned not to eat raw flour doughs or batters. Raw flour can contain harmful bacteria such as ''[[E. coli]]'' and needs to be cooked like other foods.<ref name="CDC-2021">{{cite web |title=Raw Dough Can Contain Germs That Make You Sick |website=CDC |date=28 July 2021 |url=https://www.cdc.gov/foodsafety/communication/no-raw-dough.html |access-date=21 October 2021 |archive-date=17 December 2021 |archive-url=https://web.archive.org/web/20211217011323/https://www.cdc.gov/foodsafety/communication/no-raw-dough.html |url-status=live }}</ref>

Normal processing of flour from which the outer layers have been removed (white flour) removes nutrients. Such flours, and breads made from them, may be fortified by adding nutrients; this is required by law in the UK.

== Etymology ==
The English word ''flour'' is originally a variant of the word ''[[flower]]'', and both words derive from the [[Old French]] ''fleur'' or ''flour'', which had the literal meaning "blossom", and a figurative meaning "the finest". The phrase ''fleur de farine'' meant "the finest part of the flour", since flour resulted from the elimination of coarse and unwanted matter from the grain during milling.<ref>{{cite book|title=Food: a dictionary of literal and nonliteral terms|first= Robert Allen|last= Palmatier|publisher=Greenwood|year=2000|isbn=978-0-313-31436-0|page=[https://archive.org/details/isbn_0313314365/page/136 136]|url=https://archive.org/details/isbn_0313314365|url-access=registration|location=Westport, CT}}</ref>

== History ==
[[File:Wheat P1210892.jpg|thumb|A field of unripe wheat]]
{{further|Wheat}}

[[Maize]] or corn flour has been important in [[Mesoamerica]]n cuisine since ancient times and remains a staple in the Americas. [[Rye]] flour is a constituent of bread in central and northern Europe. Archaeological evidence for making flour ([[wheat]] seeds crushed between simple [[millstone]]s) dates to at least 6000 BC. In 2018, archaeologists reported finding evidence<ref>{{Cite journal |last=Arranz-Otaegui |first=Amaia |date=31 July 2018 |title=Archaeobotanical evidence reveals the origins of bread 14,400 years ago in northeastern Jordan |journal=Proceedings of the National Academy of Sciences of the United States of America|volume=115 |issue=31 |pages=7925–7930 |doi=10.1073/pnas.1801071115 |pmid=30012614 |pmc=6077754 |bibcode=2018PNAS..115.7925A |doi-access=free }}</ref> of bread making at Shubayqa 1, a [[Natufian]] hunter-gatherer site more than 14,000 years old in northwest Jordan. The [[Ancient Rome|Romans]] were the first to grind seeds on cone [[mill (grinding)|mill]]s. In 1786, at the beginning of the [[Industrial Era]], the first steam-powered flour mill, [[Albion Mills, Southwark]], was completed in [[London]].<ref>{{cite web |url=http://www.flour-art-museum.de/english/background-and-culture/history-of-flour.html |title=The history of flour – The FlourWorld Museum Wittenburg – Flour Sacks of the World |website=www.flour-art-museum.de |language=en |access-date=2017-10-18 |archive-date=2011-04-04 |archive-url=https://web.archive.org/web/20110404033142/http://www.flour-art-museum.de/english/background-and-culture/history-of-flour.html |url-status=dead}}</ref> In the 1930s, some flour began to be enriched with iron, niacin, thiamine and riboflavin. In the 1940s, mills started to enrich flour and [[folic acid]] was added to the list in the 1990s.

=== Degermed and heat-processed flour ===

An important problem of the [[Industrial Revolution]] was the preservation of flour. Transportation distances and a relatively slow distribution system collided with natural [[shelf life]]. The reason for the limited shelf life is the [[fatty acids]] of the [[Cereal germ|germ]], which react from the moment they are exposed to oxygen. This occurs when grain is milled; the fatty acids oxidize and flour starts to become [[rancidification|rancid]]. Depending on climate and grain quality, this process takes six to nine months. In the late 19th century, this process was too short for an industrial production and distribution cycle. As [[vitamin]]s, [[micronutrient]]s and [[amino acid]]s were completely or relatively unknown in the late 19th century, removing the germ was an effective solution. Without the germ, flour cannot become rancid. Degermed flour became standard. Degermation started in densely populated areas and took approximately one generation to reach the countryside.
Heat-processed flour is flour where the germ is first separated from the endosperm and bran, then processed with steam, dry heat or [[microwave]] and blended into flour again.<ref>{{cite web |url=http://www.goldkeim.com/ |title=Deutsch: Goldkeim |website=www.goldkeim.com |language=de |access-date=2017-10-18 |archive-date=2011-02-01 |archive-url=https://web.archive.org/web/20110201180727/http://goldkeim.com/ |url-status=live}}</ref>

=== Production ===
[[File:A Walz set of roller mills.png|right|thumb|A [[Vienna bread#Hungarian high milling|Walz set]] of roller mills.]]
[[Flour mill|Milling of flour]] is accomplished by grinding grain between [[Mill stone|stones]] or steel wheels.<ref>{{cite book |chapter-url=https://books.google.com/books?id=6jRDAAAAIAAJ&pg=PA31 |title=Report on Vienna bread |author=Eben Norton Horsford |chapter=Chapter II: The Art of Milling |location=Washington |publisher=Government Printing Office |year=1875 |access-date=2015-11-22 |archive-date=2023-01-13 |archive-url=https://web.archive.org/web/20230113231527/https://books.google.com/books?id=6jRDAAAAIAAJ&pg=PA31 |url-status=live }}</ref> Today, "stone-ground" usually means that the grain has been ground in a mill in which a revolving stone wheel turns over a stationary stone wheel, vertically or horizontally with the grain in between.

== Modern mills ==
{{Main|Gristmill}}
[[Roller mill#Producing wheat flour|Roller mill]]s soon replaced stone [[grist]] mills as the production of flour has historically driven technological development, as attempts to make [[gristmill]]s more productive and less labor-intensive led to the [[watermill]]<ref>{{cite web|url=https://www.flickr.com/photos/by_jerry_jaynes/collections/72157602214123118/|title=Grist Mills|website=Flickr|date=8 June 2006|language=en-us|access-date=2017-10-18|archive-date=2020-08-02|archive-url=https://web.archive.org/web/20200802034456/https://www.flickr.com/photos/by_jerry_jaynes/collections/72157602214123118/|url-status=live}}</ref> and [[windmill]]. These terms are now applied more broadly to uses of water and wind power for purposes other than milling.<ref>{{cite web|url=https://www.angelfire.com/journal/millrestoration/roller.html|title=How the Roller Mills Changed the Milling Industry|website=[[Angelfire]]|access-date=2017-10-18|archive-date=2018-03-04|archive-url=https://web.archive.org/web/20180304180315/http://www.angelfire.com/journal/millrestoration/roller.html|url-status=live}}</ref> More recently, the [[Unifine mill]], an impact-type mill, was developed in the mid-20th century.

Modern farm equipment allows livestock farmers to do some or all of their own milling when it comes time to convert their own grain crops to coarse meal for [[animal feed|livestock feed]]. This capability is economically important because the profit margins are often thin enough in commercial farming that saving expenses is vital to staying in business.

== Composition ==
[[File:Uskladněná mouka.JPG|thumb|Flour being stored in large cloth [[flour sack|sacks]]]]
Flour contains a high proportion of [[starch]]es, which are a subset of complex [[carbohydrate]]s also known as [[polysaccharide]]s. The kinds of flour used in cooking include all-purpose flour (known as plain outside North America), self-rising flour, and cake flour (including bleached flour). The higher the protein content the harder and stronger the flour, and the more it will produce crispy or chewy breads. The lower the protein the softer the flour, which is better for cakes, cookies, and pie crusts.<ref>{{Cite news|url=http://www.buzzle.com/articles/self-rising-flour-vs-all-purpose-flour.html|title=Self-rising Flour Vs. All-purpose Flour: Know the Difference|work=Tastessence|access-date=2011-04-15|language=en-US|archive-date=2013-01-19|archive-url=https://archive.today/20130119001316/http://www.buzzle.com/articles/self-rising-flour-vs-all-purpose-flour.html|url-status=usurped}}</ref> Cereal flour consists either of the [[endosperm]], [[cereal germ|germ]], and [[bran]] together (whole-grain flour) or of the endosperm alone (refined flour).

=== Bleached flour ===

"Bleached flour" is "refined" flour with a [[flour bleaching agent|chemical whitening (bleaching) agent]] added.  "Refined" flour has had the germ and bran, containing much of the nutritional fibre and vitamins, removed and is often referred to as "white flour".

Bleached flour is artificially aged using a "bleaching" agent, a "maturing" agent, or both. A bleaching agent affects the carotenoids responsible for the natural colour of the flour; a "maturing" agent also affects [[gluten]] development. A maturing agent may either strengthen or weaken gluten development.

==== Additives ====
The four most common additives used as bleaching/maturing agents in the US are:
* [[Potassium bromate]], listed as an ingredient, is a maturing agent that strengthens gluten development. It does not bleach.
* [[Benzoyl peroxide]] bleaches, but does not act as a maturing agent. It has no effect on gluten.
* [[Ascorbic acid]] (vitamin C) is listed as an ingredient, either as an indication that the flour was matured using ascorbic acid or that a small amount is added as a dough enhancer. It is a maturing agent that strengthens gluten development, but does not bleach.
* [[Chlorine]] gas is used as both a bleaching agent and a maturing agent. It weakens gluten development and oxidizes starches, making it easier for the flour to absorb water and swell, resulting in thicker batters and stiffer doughs. The retarded gluten formation is desirable in cakes, cookies, and biscuits, as it would otherwise make them tougher and bread-like. The modification of starches in the flour allows the use of wetter doughs (making for a moister end product) without destroying the structure necessary for light, fluffy cakes and biscuits.<ref>{{Cite book| last1 = Figoni| first1 = Paula I. | title = How baking works | publisher = John Wiley & Sons| year = 2010| page = 86| isbn = 978-0-470-39267-6| url = https://books.google.com/books?id=XqKF7PqV02cC}}</ref> Chlorinated flour allows cakes and other baked goods to set faster and rise better, and the fat to be distributed more evenly, with less vulnerability to collapse.

Some other chemicals used as [[flour treatment agents]] to modify color and baking properties include:
* [[Chlorine dioxide]] (unstable to be transported in the US)
* [[Calcium peroxide]]
* [[Azodicarbonamide]] or azobisformamide (synthetic)
* Atmospheric oxygen causes natural bleaching.

Common preservatives in commercial flour include:
* [[Calcium propanoate]]
* [[Sodium benzoate]]
* [[Tricalcium phosphate]]
* [[Butylated hydroxyanisole]]

==== Frequency of additives ====

All bleaching and maturing agents (with the possible exception of ascorbic acid) have been banned in the United Kingdom.<ref>{{cite web|url= http://www.food.gov.uk/multimedia/pdfs/breadflourguide.pdf|title= The Bread and Flour Regulations 1998 – Guidance Notes|date= 1 June 2008|publisher= Food Standards Agency|access-date= 29 March 2012|archive-date= 9 December 2011|archive-url= https://web.archive.org/web/20111209193220/http://www.food.gov.uk/multimedia/pdfs/breadflourguide.pdf|url-status= live}}</ref>

Bromination of flour in the US has fallen out of favor, and while it is not yet actually banned anywhere, few retail flours available to the home baker are bromated anymore.

Many varieties of flour packaged specifically for commercial bakeries are still bromated. Retail bleached flour marketed to the home baker is now treated mostly with either peroxidation or chlorine gas. Current information from Pillsbury is that their varieties of bleached flour are treated both with benzoyl peroxide and chlorine gas. Gold Medal states that their bleached flour is treated either with benzoyl peroxide or chlorine gas, but no way exists to tell which process has been used when buying the flour at the grocery store.

====Old method of bleaching====
The old method of procuring white or "bleached" flour did not entail the use of chemical agents at all. Rather, the [[Wheat berry|wheat kernels]] were moistened with water long enough for the outer kernels of the wheat which contained the [[bran]] to soften and, eventually, fall off while grinding.<ref>[[Babylonian Talmud]] (''[[Pesachim]]'' 40a), Quote: "It is impossible to obtain a clean, white bread without moistening [the grain]" ({{langx|he|אי אפשר נקיה בלא לתיתה}}).</ref> In some places, the leaves of Syrian rue (''[[Peganum harmala]]'') were spread in stratified layers between the layers of grain, and left in such a state for several days, until the fumes emitted from the astringent leaves of the plant caused the outer kernels of the wheat to break down and dissolve, leaving a clean and white flour after grinding.<ref>{{cite book |last=Saleh|first=Y. |author-link=Yiḥyah Salaḥ |title=Questions & Responsa 'Pe'ulath Ṣadīq'|volume=1 |edition=2nd |date=1979 |location=Jerusalem |page=109 |language=he |oclc=122773689 }} ({{OCLC|122773689}}), ''responsum'' no. 171</ref><ref>{{cite book |last=Qafih |first=Y. |author-link=Yosef Qafih|title=Halichot Teman (Jewish Life in Sanà) |publisher=[[Ben-Zvi Institute]] |date=1982 |location=Jerusalem |page=15 |language=he |isbn=965-17-0137-4 |oclc=863513860 }}</ref><ref>{{Citation |contribution=Hil. Ḥametz u'matzah |title=Sefer Mishneh Torah |editor-last=Qafih |editor-first=Y. |editor-link=Yosef Qafih |edition=4 |volume=4 (Zemanim) |publisher=Mekhon mishnat ha-Rambam|place=Kiryat Ono|year=2011 |page=342 (note 14) |language=he |oclc=187478401 |title-link=Mishneh Torah}}, s.v. ''Ḥametz u'matzah'' 5:8</ref><ref>{{Citation |contribution=Scholars of Yemen Answer Questions of Rabbi A.I. Kook |title=Ascending the Palm Tree: An Anthology of the Yemenite Jewish Heritage|last=Gaimani|first=Aharon|editor1=Rachel Yedid|editor2=Danny Bar-Maoz|publisher=E'ele BeTamar|place=Rehovot|year=2018 |page=115 |oclc=1041776317 |isbn=978-965-7121-33-7}}</ref>

=== Enriched flour ===
{{Main|Enriched flour}}
During the process of making flour, specifically as a result of the bleaching process, nutrients are lost. Some of these nutrients may be replaced during refining – the result is known as ''enriched'' flour. In the UK most flour, and consequently breads made with it, is required to be fortified with added calcium, iron, thiamine (Vitamin B1) and niacin (Vitamin B3); wholemeal flour is exempt as it inherently contains sufficient of these nutrients.<ref>{{cite web | title=Bread and Flour Regulations | publisher=UK Flour Millers | date=October 2023| url=https://www.ukflourmillers.org/bread-and-flour-regulations}}</ref>

=== Cake flour ===
Cake flour is the lowest in gluten protein content, with 6–7%<ref name="Reinhart-2001">{{Cite book|title=The Bread Baker's Apprentice|last=Reinhart|first=Peter|publisher=Ten Speed Press|year=2001|isbn=978-158008-268-6|location=Berkeley, California|page=29}}</ref> (5–8% from second source<ref name="Food Network-2018">{{cite web|url=http://www.foodnetwork.com/recipes/packages/baking-guide/flour-101-guide-to-different-types-and-uses|title=Different Flour Types|website=Food Network|access-date=2018-01-04|archive-date=2018-01-05|archive-url=https://web.archive.org/web/20180105123050/http://www.foodnetwork.com/recipes/packages/baking-guide/flour-101-guide-to-different-types-and-uses|url-status=live}}</ref>) protein to produce minimal binding so the cake "crumbles" easily.

=== Pastry flour ===
Pastry flour has the second-lowest gluten protein content, with 7.5–9.5%<ref name="Reinhart-2001" /> (8–9% from second source<ref name="Food Network-2018" />) protein to hold together with a bit more strength than cakes, but still produce flaky crusts rather than hard or crispy ones.

=== Plain or all-purpose flour ===
All-purpose, or "AP flour", or plain flour is medium in gluten protein content at 9.5–11.5%<ref name="Reinhart-2001" /> (10–12% from second source<ref name="Food Network-2018" />) protein content.  It has adequate protein content for many bread and pizza bases, though bread flour and special 00 grade Italian flour are often preferred for these purposes, respectively, especially by artisan bakers. Some biscuits are also prepared using this type of flour. "Plain" refers not only to AP flour's middling gluten content but also to its lack of any added leavening agent (as in self-rising flour).

=== Bread flour ===
Bread flour is typically made from [[hard red winter wheat]] planted in the fall and harvested in the spring. Hard wheat is high in gluten, a protein that makes dough stretchy. Hard wheat is 11.5–13.5%<ref name="Reinhart-2001" /> (12–14% from second source<ref name="Food Network-2018" />) protein. The increased protein binds to the flour to entrap [[carbon dioxide]] released by the yeast [[fermentation (food)|fermentation]] process, resulting in a better rise and chewier texture.

=== Hard flour ===
Hard is a general term for flours with high gluten protein content, commonly refers to extra strong flour, with 13.5–16%<ref name="Reinhart-2001" /> (or 14–15% from some sources) protein (16% is a theoretically possible protein content<ref name="Reinhart-2001" />).  This flour may be used where a recipe adds ingredients that require the dough to be extra strong to hold together in their presence, or when strength is needed for constructions of bread (e.g., some centerpiece displays).

=== Gluten flour ===
Gluten flour is refined gluten protein, or a theoretical 100% protein (though practical refining never achieves a full 100%). It is used to strengthen flour as needed.  For example, adding approximately one teaspoon per cup of AP flour gives the resulting mix the protein content of bread flour.  It is commonly added to whole grain flour recipes to overcome the tendency of greater fiber content to interfere with gluten development, needed to give the bread better rising (gas holding) qualities and chew.

=== Unbleached flour ===
Unbleached flour is simply flour that has not undergone bleaching and therefore does not have the color of "white" flour. An example is [[graham flour]], whose namesake, [[Sylvester Graham]], was against using bleaching agents, which he considered unhealthy.

=== Self-raising flour ===
In English-speaking countries, self-raising (or self-rising) flour is commercially available with chemical [[leavening agent]]s already in the mix.<ref>[http://bakingbites.com/2007/08/what-is-self-rising-flour/ Self-rising flour] {{Webarchive|url=https://web.archive.org/web/20110616010925/http://bakingbites.com/2007/08/what-is-self-rising-flour/ |date=2011-06-16 }} -Retrieved 2011-04-15</ref><ref>[https://www.nigella.com/ask/self-rising-flour-substitution/ Nigella Lawson] {{Webarchive|url=https://web.archive.org/web/20210412195950/https://www.nigella.com/ask/self-rising-flour-substitution |date=2021-04-12 }} -Retrieved 2021-03-13</ref> In America, it is also likely to be pre-salted; in Britain this is not the case. The added ingredients are evenly distributed throughout the flour, which aids a consistent rise in baked goods. This flour is generally used for preparing sponge cakes, scones, muffins, etc. It was invented by [[Henry Jones (baker)|Henry Jones]] and patented in 1845. If a recipe calls for self-raising flour, and this is not available, the following substitution is possible:
* 1 cup (125&nbsp;g) plain flour
* 1 teaspoon (3&nbsp;g) [[baking powder]]
* (US recipes) a pinch to {{frac|1|4}} teaspoon (1&nbsp;g or less) [[salt]]

== Types ==

=== Gluten-containing flours ===

==== Wheat flour ====
{{Main|Wheat flour}}
Wheat is the grain most commonly used to make flour.{{citation needed|date=May 2018}} Certain varieties may be referred to as "clean" or "white". Flours contain differing levels of the protein [[gluten]]. "Strong flour" or "hard flour" has a higher gluten content than "weak" or "soft" flour. "Brown" and wholemeal flours may be made of hard or soft wheat.
* [[Atta flour]] is a whole-grain wheat flour important in Indian and Pakistani cuisine, used for a range of breads such as [[roti]] and [[chapati]]. It is usually stone-ground to coarse granules, which gives it a texture not easily found in other flatbreads.
* [[Common wheat]] flour (''T.&nbsp;aestivum'') is the flour most often used for making bread. [[Durum wheat]] flour (''T.&nbsp;durum'') is the second most used.<ref name=Cooper>{{cite journal |author=Cooper R|title=Re-discovering ancient wheat varieties as functional foods|journal=J Tradit Complement Med|volume=5|issue=3|pages=138–43|date=Mar 29, 2015|pmid=26151025|pmc=4488568|doi=10.1016/j.jtcme.2015.02.004}}</ref>
* [[Maida flour]] is a finely milled wheat flour used to make a wide variety of Indian breads such as paratha and naan. Maida is widely used not only in Indian cuisine but also in Central Asian and Southeast Asian cuisine. Though sometimes referred to as "all-purpose flour" by Indian chefs, it more closely resembles cake flour or even pure starch. In India, maida flour is used to make pastries and other bakery items such as bread, biscuits and toast.
* [[Noodle]] flour is a special blend of flour used for the making of Asian-style noodles, made from wheat or rice.
* [[Semolina]] is the coarse, purified [[wheat middlings]] of durum wheat used in making pasta, breakfast cereals, puddings, and couscous.
* [[Spelt]], an ancient grain, is a hexaploid species of wheat.<ref name=Cooper /> Spelt dough needs less kneading than common wheat or durum wheat dough.{{citation needed|date=December 2015}} Compared to hard-wheat flours, spelt flour has a relatively low (six to nine percent) protein count, just a little higher than pastry flour.{{citation needed |date=November 2013 |reason=skeptical of protein level, spelt page says protein roughly 14%}} That means that plain spelt flour works well in creating dough for soft foods such as cookies or pancakes. Crackers turn out well because they are made from dough that does not need to rise when baked.{{citation needed|date=December 2015}}

==== Other varieties ====<!-- This section is linked from [[Suet]] -->
[[File:E8088-Alamudun-Bazaar-flour-vendor.jpg|thumb|A variety of types of flour and cereals sold at a bazaar in [[Bishkek]], [[Kyrgyzstan]]]]
* [[Rye]] flour is used to bake the traditional [[sourdough]] breads of Germany, Austria, Switzerland, Russia, [[Czech Republic]], Poland and [[Scandinavia]]. Most [[rye bread]]s use a mix of rye and wheat flours because rye does not produce sufficient gluten. [[Pumpernickel]] bread is usually made exclusively of rye, and contains a mixture of rye flour and rye meal. [[Secale]] flower is used to make bread such as [[Prądnik bread]].

=== Gluten-free flours ===
When flours do not contain gluten, they are suitable for people with [[gluten-related disorders]], such as [[coeliac disease]], [[non-celiac gluten sensitivity]] or [[wheat allergy]] sufferers, among others.<ref name=TovoliMasi>{{cite journal|vauthors=Tovoli F, Masi C, Guidetti E, Negrini G, Paterini P, Bolondi L|title=Clinical and diagnostic aspects of gluten related disorders|journal=World J Clin Cases|volume=3|issue=3|pages=275–84|date=Mar 16, 2015|pmid=25789300|pmc= 4360499|doi=10.12998/wjcc.v3.i3.275 |doi-access=free }}</ref><ref name=Akobeng2008>{{Cite journal|author=Akobeng AK, Thomas AG |title=Systematic review: tolerable amount of gluten for people with coeliac disease|journal=Aliment Pharmacol Ther|volume=27|issue=11|pages=1044–52|date=June 2008|pmid=18315587|doi=10.1111/j.1365-2036.2008.03669.x|s2cid=20539463|doi-access=free}}</ref><ref name=SeeKaukinen>{{cite journal|vauthors=See JA, Kaukinen K, Makharia GK, Gibson PR, Murray JA|title=Practical insights into gluten-free diets|journal=Nat Rev Gastroenterol Hepatol|volume=12|issue=10|pages=580–91|date=Oct 2015|pmid=26392070|doi=10.1038/nrgastro.2015.156|s2cid=20270743}}</ref><ref name=FSAI>{{cite web|url=https://www.fsai.ie/uploadedfiles/legislation/consultations/info_270204.pdf|title=Guidelines to Prevent Cross-Contamination of Gluten-free Foods|publisher=Food Safety Authority of Ireland|access-date=Dec 20, 2015|url-status=dead|archive-url=https://web.archive.org/web/20160305013411/https://www.fsai.ie/uploadedfiles/legislation/consultations/info_270204.pdf|archive-date=2016-03-05}}</ref> Contamination with gluten-containing cereals can occur during grain harvesting, transporting, milling, storing, processing, handling and/or cooking.<ref name=FSAI /><ref name=CominoMoreno>{{cite journal|vauthors=Comino I, Moreno Mde L, Real A, Rodríguez-Herrera A, Barro F, Sousa C|title=The gluten-free diet: testing alternative cereals tolerated by celiac patients|journal=Nutrients|volume=5|issue=10|pages=4250–68|date=Oct 23, 2013|pmid=24152755|pmc=3820072|doi=10.3390/nu5104250|doi-access=free}}</ref><ref name=HuttneraArednt>{{cite journal|vauthors=Hüttnera EK, Arednt EK|title=Recent advances in gluten-free baking and the current status of oats|journal=Trends in Food Science & Technology|volume=21|issue=6|pages=303–12|date=June 2010|doi=10.1016/j.tifs.2010.03.005}}</ref>
* [[Acorn]] flour is made from ground acorns and can be used as a substitute for wheat flour. It was used by Native Americans. Koreans also use acorn flour to make [[dotorimuk]].
* [[Almond meal|Almond flour]] is made from ground almonds.
* [[Amaranth]] flour is a flour produced from ground amaranth grain. It was commonly used in pre-Columbian meso-American cuisine and was originally cultivated by the Aztecs. It is becoming more and more available in speciality food shops.
* [[Apple flour]] is made from milling apple pomace, the solid remains of juiced apples.
* [[Banana flour]] has been traditionally made of green bananas for thousands of years and is currently popular both as a gluten-free replacement for wheat flour and as a source of [[resistant starch]].
* [[Bean]] flour is a flour produced from pulverized dried or ripe beans. [[Chickpea|Garbanzo]] and [[vicia faba|fava bean]] flour is a flour mixture with a high nutritional value and strong aftertaste.
* [[Brown rice]] flour is of great importance in [[Southeast Asian cuisine]]. Edible [[rice paper]] can be made from it.
* [[Buckwheat]] flour is used as an ingredient in many [[pancake]]s in the United States. In Japan, it is used to make a popular noodle called [[soba]]. In Russia, buckwheat flour is added to the batter for pancakes called ''[[blini]]s'' which are frequently eaten with [[caviar]]. Buckwheat flour is also used to make [[Crêpe|crêpes bretonnes]] in [[Brittany]]. On Hindu fasting days (''[[Navaratri]]'' mainly, also ''[[Maha Shivaratri]]''), people eat food made with buckwheat flour. The preparation varies across India. The most famous dishes are ''[[Buckwheat|kuttu]] ki puri'' and ''kuttu [[pakora]]''. In most northern and western states the usual term is ''kuttu ka atta''.
* [[Cassava]] flour is made from the root of the [[cassava]] plant. In a purified form (pure starch), it is called [[tapioca]] flour (see in list below).
* [[Sweet Chestnut|Chestnut]] flour is popular in [[Corsica]], the [[Périgord]], and [[Lunigiana]] for breads, [[cake]]s and [[pasta]]s. It is the original ingredient for [[Polenta#Description|polenta]], still used as such in Corsica and other Mediterranean locations. Chestnut bread keeps fresh for as long as two weeks.<ref name=grocer>[http://digital.lib.msu.edu/projects/cookbooks/books/grocersencyclopedia/ency.html ''The Grocer's Encyclopedia - Encyclopedia of Foods and Beverages''] {{Webarchive|url=https://wayback.archive-it.org/all/20100212203301/http://digital.lib.msu.edu/projects/cookbooks/books/grocersencyclopedia/ency.html |date=2010-02-12 }}. By Artemas Ward. New York. 1911.</ref> In other parts of Italy it is mainly used for [[dessert]]s.
* [[Chickpea]] flour (also known as [[gram flour]] or besan) is of great importance in [[Indian cuisine]], and in Italy, where it is used for the [[Liguria]]n [[farinata]].
* [[Chuño]] flour is made from dried potatoes in various countries of South America.
* [[Coconut]] flour is made from ground coconut meat and has the highest fiber content of any flour, having a very low concentration of digestible carbohydrates and thus making an excellent choice for those looking to restrict their carbohydrate intake. It also has a high fat content of about 60 percent.
* Finely ground [[maize]], known as [[Maize flour|corn flour]] in the US, is popular in the [[Southern United States|Southern]] and [[Southwestern United States|Southwestern]] US, Mexico, [[Central America]], and [[Punjab region]]s of India and Pakistan, where it is called ''makai ka atta''. Coarse whole-grain corn flour is usually called [[cornmeal]]. Finely ground corn flour that has been treated with food-grade lime is called ''masa harina'' (see ''[[masa]]'') and is used to make ''[[tortilla]]s'' and ''[[tamale]]s'' in Mexican cooking. In Britain "cornflour" is the term for what is known as [[corn starch]] in the US.<ref>{{cite dictionary| title=cornflour| dictionary=Oxford Advanced Learner's Dictionary| url=https://www.oxfordlearnersdictionaries.com/definition/english/cornflour}}</ref>
** [[Cornmeal]] is very similar to corn flour (see above) except in a coarser grind.
** [[Corn starch]] is starch extracted from endosperm of the corn kernel.
* [[Glutinous rice]] flour or sticky rice flour is used in east and southeast Asian cuisines for making [[tangyuan (food)|tangyuan]], etc.
* [[Hemp]] flour is produced by pressing the oil from the hemp seed and milling the residue. Hemp seed is approximately 30 percent oil and 70 percent residue. Hemp flour does not rise, and is best mixed with other flours. Added to any flour by about 15–20 percent, it gives a spongy nutty texture and flavor with a green hue.
* [[Mesquite flour]] is made from the dried and ground pods of the [[mesquite]] tree, which grows throughout North America in arid climates. The flour has a sweet, slightly nutty flavor and can be used in a wide variety of applications.<ref>{{cite web | url=http://chetday.com/mesquiteflour.htm | title=Mesquite, the Rediscovered Food Phenomenon | access-date=2010-06-23 | archive-date=2011-07-08 | archive-url=https://web.archive.org/web/20110708143259/http://chetday.com/mesquiteflour.htm | url-status=live }}</ref>
* [[Nut (fruit)|Nut]] flours are grated from oily nuts—most commonly almonds and [[hazelnut]]s—and are used instead of or in addition to wheat flour to produce more dry and flavorful pastries and cakes. Cakes made with nut flours are usually called [[torte]]s and most originated in Central Europe, in countries such as Hungary and Austria.
* [[Peasemeal]] or pea flour is a flour produced from roasted and pulverized yellow field peas.
* [[Peanut flour]] made from shelled cooked peanuts is a high-protein alternative to regular flour.<ref>{{cite web |url=http://www.goldenpeanut.com/flour.aspx |title=Bulk Walnuts &#124; Wholesale Macadamia Products &#124; Cashews &#124; Seeds &#124; Golden Peanut |access-date=2010-11-27 |url-status=dead |archive-url=https://web.archive.org/web/20101208072006/http://www.goldenpeanut.com/Flour.aspx |archive-date=2010-12-08 }} -Peanut flour</ref>
* [[Potato starch]] flour is obtained by grinding the tubers to a pulp and removing the fibre and protein by water-washing. Potato starch (flour) is very white starch powder used as a thickening agent. Standard (native) potato starch needs boiling, to thicken in water, giving a transparent gel. Because the flour is made from neither grains nor legumes, it is used as a substitute for wheat flour in cooking by [[Jew]]s during [[Passover]], when grains are not eaten.
* [[Potato]] flour, often confused with potato starch, is a peeled, cooked potato powder of mashed, mostly [[drum drying|drum-dried]] and ground potato flakes using the whole potato and thus containing the protein and some of the fibres of the potato. It has an off-white slight yellowish color.<ref>Jack Augustus Radley, ''[https://books.google.com/books?id=nNSJDzezG0UC&dq=potato+starch+and+alcohol&pg=PA71 Industrial Uses of Starch and Its Derivatives]'', lk 71, 1976, Applied Science Publishers Ltd, {{ISBN|0 85334 6917}}, Google'i raamat veebiversioon (vaadatud 30.11.2013) (''inglise keeles'')</ref> These [[dehydrate]]d, dried, potatoes, also called [[instant mashed potatoes]] can also be granules or flakes.<ref>{{cite web |url=http://www.idahopacific.com/index.html |title=Idaho Pacific Corporation, The best potatoes that Idaho has to offer |publisher=Idahopacific.com |access-date=2011-10-31 |archive-date=2011-09-06 |archive-url=https://web.archive.org/web/20110906091103/http://www.idahopacific.com/index.html |url-status=live }}</ref> Potato flour is cold-water-soluble; however, it is not used often as it tends to be heavy.
* [[Rice flour]] is ground kernels of rice. It is a staple in [[Asia]]. It is also widely used in Western countries, especially for people who suffer from [[gluten-related disorders]]. Brown rice flour has higher nutritional value than white rice flour.
* [[Sorghum]] flour is made from grinding whole grains of the sorghum plant. It is called ''jowar'' in India.
* [[Tapioca]] flour, produced from the root of the [[cassava]] plant, is used to make breads, pancakes, [[tapioca pudding]], a savoury porridge called [[fufu]] in Africa, and is used as a starch.
* [[Eragrostis tef|Teff]] flour is made from the grain teff, and is of considerable importance in [[East Africa|eastern Africa]] (particularly around the [[Horn of Africa]]). Notably, it is the chief ingredient in the bread [[injera]], an important component of Ethiopian cuisine.

==== More types ====
{{Main|List of edible seeds}}

Flour also can be made from [[Soy flour|soybeans]], [[arrowroot]], [[taro]], [[Typha|cattail]]s, [[manioc]], [[quinoa]], and other non-cereal foodstuffs.

{{anchor|Flour_type_numbers}} {{anchor|flour_type_numbers}}

=== Type numbers ===

In some markets, the different available flour varieties are labeled according to the ash mass that remains after a sample is incinerated in a [[laboratory oven]] (typically at {{convert|550|C}} or {{convert|900|C}}, see [[international standard]]s [[International Organization for Standardization|ISO]] 2171 and [[International Association for Cereal Science and Technology|ICC]] 104/1<ref>{{cite web |url=https://icc.or.at/publications/icc-standards/standards-overview/104-1-standard-method |title=104/1 Determination of Ash in Cereals and Cereal Products |publisher=International Association for Cereal Science and Technology |date=8 March 2018 |access-date=29 January 2021 |archive-date=3 February 2021 |archive-url=https://web.archive.org/web/20210203162913/https://icc.or.at/publications/icc-standards/standards-overview/104-1-standard-method |url-status=live }}</ref>). This is an easily verified indicator for the fraction of the whole grain remains in the flour, because the mineral content of the starchy endosperm is much lower than that of the outer parts of the grain. Flour made from all parts of the grain ([[milling yield|extraction rate]]: 100%) leaves about {{convert|2|g}} ash or more per {{convert|100|g}} dry flour. Plain white flour with an extraction rate of 50–60% leaves about {{convert|0.4|g}}.
* German flour type numbers ({{lang|de|Mehltypen}}) indicate the amount of ash (measured in milligrams) obtained from 100&nbsp;g of the dry mass of this flour. Standard wheat flours (defined in [[DIN]] 10355) range from type 405 for normal white wheat flour for baking, to strong bread flour types 550, 812, and the darker types 1050 and 1600 for wholegrain breads.
* French flour type numbers ({{lang|fr|type de farine}}) are a factor of 10 smaller than those used in Germany, because they indicate the ash content (in milligrams) per 10&nbsp;g flour. Type 55 is the standard, hard-wheat white flour for baking, including puff pastries ({{lang|fr|pâte feuilletée}}). Type 45 is often called pastry flour, and is generally from a softer wheat (this corresponds to what older French texts call {{lang|fr|farine de gruau}}). Some recipes use type 45 for croissants, for instance,<ref>{{cite web |url=http://www.supertoinette.com/fiche-cuisine/423/farine-de-ble.html |title=Supertoinette page in French on flour types |publisher=Supertoinette.com |access-date=2011-10-31 |archive-date=2011-11-01 |archive-url=https://web.archive.org/web/20111101133958/http://www.supertoinette.com/fiche-cuisine/423/farine-de-ble.html |url-status=live }}</ref> although many French bakers use type 55 or a combination of types 45 and 55.{{citation needed|date=January 2021}} Types 65, 80, and 110 are strong bread flours of increasing darkness, and type 150 is a wholemeal flour.
* Czech flour types describes roughness of milling instead of amount of ash, though sometimes a numbering system is used, it is not a rule. Czechs determine following four basic types of mill: extra soft wheat flour ({{lang|cs|výběrová hladká mouka}}, 00), soft wheat flour ({{lang|cs|hladká mouka}}, T650), fine wheat flour ({{lang|cs|polohrubá mouka}}), rough wheat flour ({{lang|cs|hrubá mouka}}) and farina wheat flour ({{lang|cs|pšeničná krupice}})
* Argentine flour uses roughness of milling as well, being 0, 00, 000 and 0000, where the number of zeroes indicates its refinement.
* Polish flour type numbers, as is the case in Germany, indicate the amount of ash in 100&nbsp;g of the dry mass of the flour. Standard wheat flours (defined by the [[Polish Committee for Standardization|PKN]] in PN-A-74022:2003) range from type 450 to 2000.<ref name="Polski Stds">Polskie Normy: ''PN-A-74022:2003 Przetwory zbożowe. Mąka pszenna'' (Wheat flour) and ''PN-A-74032: 2002 Przetwory zbożowe. Mąka żytnia'' (Rye flour).</ref>

In the United States and the United Kingdom, no numbered standardized flour types are defined, and the ash mass is only rarely given on the label by flour manufacturers. However, the legally required standard nutrition label specifies the protein content of the flour, which is also a way for comparing the extraction rates of different available flour types.

In general, as the extraction rate of the flour increases, so do both the protein and the ash content. However, as the extraction rate approaches 100% (whole meal), the protein content drops slightly, while the ash content continues to rise.

The following table shows some typical examples of how protein and ash content relate to each other in wheat flour:

{| class=wikitable
|-
!rowspan=2|Residual ash mass
!rowspan=2|Protein
! colspan="10" |Wheat flour type
|-
!US||UK||German/Polish||French||Italian||Czech/Slovak||Polish<ref name="Polski Stds"/>||Argentine||Japanese
!Chinese
|-
|~0.4%||~9%||Pastry flour||Soft flour||405||45||00||Hladká mouka výběrová 00||tortowa||0000||Hakurikiko (薄力粉)
|dījīn miànfěn (低筋麵粉)
|-
|~0.55%||~11%||All-purpose flour||Plain flour||550||55||0||Hladká mouka||luksusowa||000||Churikiko (中力粉)
|zhōngjīn miànfěn (中筋麵粉)
|-
|~0.8%||~14%||Bread flour or "high gluten flour"||Strong or hard||812||80||1||Polohrubá mouka||chlebowa||00||Kyorikiko (強力粉)
|gāojīn miànfěn (高筋麵粉)
|-
|~1.1%||~15%||First clear flour||Very strong or hard||1050||110||2||Hrubá mouka||sitkowa||0||kyorikimatsufun (強力末粉)
|tè gāojīn miànfěn (特高筋麵粉)
|-
|>1.5%||~13%||White whole wheat||Wholemeal||1600||150||Farina integrale di grano tenero||Celozrnná mouka||graham, razowa||{{frac|1|2}} 0||Zenryufun (全粒粉)
|quánmài miànfěn (全麥麵粉)
|}

This table is only a rough guideline for converting bread recipes. Since flour types are not standardized in many countries, the numbers may differ between manufacturers. There is no French type corresponding to the lowest ash residue in the table. The closest is French Type 45.

There is no official Chinese name corresponding to the highest ash residue in the table. Usually such products are imported from Japan and the Japanese name ''zenryufun'' (全粒粉) is used, or it is called ''quánmài miànfěn'' (全麥麵粉).

It is possible to determine ash content from some US manufacturers. However, US measurements are based on wheat with a 14% moisture content. Thus, a US flour with 0.48% ash would approximate a French Type 55.

Other measurable properties of flour as used in [[baking]] can be determined using a variety of specialized instruments, such as the [[farinograph]].

== Dangers ==

=== Flammability ===
Flour dust suspended in air is [[explosive]]—as is any mixture of a finely powdered flammable substance with air<ref>{{cite web |url=http://www.chemeng.ed.ac.uk/~emju49/SP2001/webpage/index.html |title=Introduction to Dust Explosions |access-date=2006-10-29 |last=Williamson |first=George |date=2002 |archive-url=https://web.archive.org/web/20041223145242/http://www.chemeng.ed.ac.uk/~emju49/SP2001/webpage/index.html |archive-date=2004-12-23 }}</ref> (''see'' [[dust explosion]]). Some devastating explosions have occurred at flour mills, including an explosion in 1878 at the [[Washburn "A" Mill]] in [[Minneapolis]] that killed 22 people.<ref>{{cite web |url=http://www.mnhs.org/library/tips/history_topics/73washburn.html |title=Washburn 'A' Mill Explosion |access-date=2006-10-29 |work=Minnesota Historical Society Library History Topics |archive-date=2013-07-31 |archive-url=https://web.archive.org/web/20130731014659/http://www.mnhs.org/library/tips/history_topics/73washburn.html |url-status=live }}</ref><ref>{{Cite book|url=https://books.google.com/books?id=p4o9AQAAIAAJ|title=Scientific American, "The Explosiveness of Flour"|date=1878-08-10|publisher=Munn & Company|page=87|language=en}}</ref>

=== Pathogens ===
The [[Centers for Disease Control and Prevention|CDC]] has cautioned not to eat raw flour doughs or batters. Raw flour can contain bacteria like ''[[Escherichia coli|E.&nbsp;coli]]'' and needs to be cooked like other foods.<ref name="CDC-2021" />

== Products ==
[[Bread]], [[pasta]], [[Cracker (food)|cracker]]s, many [[cake]]s, and many other foods are made using flour. Wheat flour is also used to make a [[roux]] as a base for thickening gravy and sauces.
It can also be used as an [[ingredient]] in [[papier-mâché]] [[glue]].<ref>{{cite web|title=Make Paper Mache Glue|url=http://www.kidspot.com.au/things-to-do/activities/make-paper-mache-glue|website=Kidspot|access-date=8 July 2017|archive-date=10 July 2017|archive-url=https://web.archive.org/web/20170710151503/http://www.kidspot.com.au/things-to-do/activities/make-paper-mache-glue|url-status=live}}</ref>

Cornstarch is a principal ingredient used to thicken many [[pudding]]s or desserts, and is the main ingredient in packaged custard.

== See also ==

* [[Groat (grain)]]
* [[Ultra-processed food]]

== References ==

{{reflist}}

== Sources ==

{{refbegin}}
* [http://www.opsi.gov.uk/si/si1998/19980141.htm The Bread and Flour Regulations 1998, United Kingdom] {{Webarchive|url=https://web.archive.org/web/20060221185414/http://www.opsi.gov.uk/si/si1998/19980141.htm |date=2006-02-21 }}
* {{Grocers}}
{{refend}}

== External links ==

{{Commons category}}
{{Cookbook}}
{{Wikiquote}}

* {{Cite NIE|wstitle=Flour|short=x}}
* [https://flour-art-museum.de/english/index.php Flourworld Museum]

{{Wheat}}
{{Bread}}
{{Authority control}}

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