Yogurt

Yogurt(UK:/ˈjɒɡət/;US:/ˈjoʊɡərt/,fromOttoman Turkish:یوغورت,romanized:yoğurt;also spelledyoghurt,yogourtoryoghourt) is a food produced by bacterialfermentationof milk.Fermentation of sugars in the milk by these bacteria produceslactic acid, which acts onmilk proteinto give yogurt itstextureand characteristic tart flavor.Cow's milk is most commonly used to make yogurt. Milk fromwater buffalo, goats,ewes,mares, camels, andyaksis also used to produce yogurt. The milk used may behomogenizedor not. It may bepasteurizedorraw. Each type of milk produces substantially different results.
Yogurt is produced using a culture ofLactobacillus delbrueckiisubsp.bulgaricusandStreptococcus thermophilusbacteria. Otherlactobacilliandbifidobacteriaare sometimes added during or after culturing yogurt. Some countries require yogurt to contain a specific amount ofcolony-forming units(CFU) of bacteria; for example, in China the requirement for the number of lactobacillus bacteria is at least 1 million CFU per milliliter.Some countries also regulate which bacteria can be used: for example, in France,a product can only be labeled as "yaourt" or "yoghourt" if it has been fermented exclusively byLactobacillus delbrueckii subsp. bulgaricusandStreptococcus thermophilus, a requirement that aligns with the international definition of yogurt in the Codex Alimentarius on fermented milk (CXS 243-2003.
The bacterial culture is mixed in, and a warm temperature of 30–45 °C (86–113 °F) is maintained for 4 to 12 hours to allow fermentation to occur, with the higher temperatures working faster but risking a lumpy texture or whey separation.
The word for yogurt is derived from theOttoman Turkish:یوغورت,romanized:yoğurt,and is usually related to the verbyoğurmak, "to knead", or "to be curdled or coagulated; to thicken".It may be related toyoğun, meaning thick or dense. The sounds historically represented by the Arabic letterghaynin the Turkish language ranging from avoiced velar fricativeto avoiced velar plosivewere traditionally romanized as "gh" prior to the introduction of anew Latin-based Turkish alphabetand the letter "ğ" in 1929, thus "yoghurt" spelled with a "gh" is first attested in sources from 1615 to 1625.
In English, spelling variations includeyogurt,yoghurt, and to a lesser extentyoghourtoryogourt.In the United Kingdom, Australia, New Zealand and South Africa the word is usually spelledyoghurt, while in the United States the spelling isyogurt. Canada has its own spelling,yogourt, a minority variant of the Frenchyaourt, althoughyogurtandyoghurtare also used.
Analysis of theL. delbrueckiisubsp.bulgaricusgenome indicates that the bacterium may have originated on the surface of a plant.Milk may have become spontaneously and unintentionally exposed to it through contact with plants, or bacteria may have been transferred from the udder of domestic milk-producing animals.The origins of yogurt are unknown but it was probably discovered first byNeolithicpeople inCentral AsiaandMesopotamiaaround 5000 BC, when the first milk-producing animals were domesticated. They most likely found out how tofermentmilk by chance and in all likelihood, yogurt was discovered independently in this way in many different places at different times.
The cuisine ofancient Greeceincluded adairy productknown asoxygala(οξύγαλα) which was a form of yogurt.Galen(AD 129 –c.200/c.216) mentioned that oxygala was consumed withhoney, similar to the way thickened Greek yogurt is eaten today.The oldest writings mentioning yogurt are attributed toPliny the Elder, who remarked that certain "barbarous nations" knew how "to thicken the milk into a substance with an agreeable acidity".The use of yogurt by medievalTurksis recorded in the booksDīwān Lughāt al-TurkbyMahmud KashgariandKutadgu BiligbyYusuf Has Hajibwritten in the 11th century.Both texts mention the word "yogurt" in different sections and describe its use by nomadic Turks.The earliest yogurts were probably spontaneouslyfermentedby wild bacteria in goat skin bags.
Some accounts suggest thatMughal IndianemperorAkbar's cooks would flavor yogurt with mustard seeds and cinnamon.Another early account of a European encounter with yogurt occurs in French clinical history:Francis Isuffered from a severediarrheawhich no French doctor could cure. His allySuleiman the Magnificentsent a doctor, who allegedly cured the patient with yogurt.The grateful king told many of the food that had cured him.
Until the 1900s, yogurt was a staple in diets of people in theRussian Empire(and especially Central Asia and theCaucasus), Western Asia,South Eastern Europe/Balkans, Central Europe, and theIndian subcontinent.Stamen Grigorov(1878–1945), a Bulgarian student of medicine inGeneva, first examined the microflora of the Bulgarian yogurt. In 1905, he described it as consisting of a spherical and a rod-like lactic acid-producing bacteria. In 1907, the rod-like bacterium was calledBacillus bulgaricus(nowLactobacillus delbrueckiisubsp.bulgaricus). The RussianbiologistandNobel laureateIlya Mechnikov, from theInstitut Pasteurin Paris, was influenced by Grigorov's work and hypothesized that regular consumption of yogurt was responsible for the unusually long lifespans ofBulgarianpeasants.BelievingLactobacillusto be essential for good health, Mechnikov worked to popularize yogurt as a foodstuff throughout Europe.
Industrialization of yogurt production is credited toIsaac Carasso, who, in 1919, started a small yogurt business inBarcelona, Spain, naming the businessDanone("little Daniel") after his son.The brand later expanded to the United States under an Americanized version of the name,Dannon.Yogurt with added fruitjamwas patented in 1933 by the Radlická Mlékárna dairy inPrague.
Yogurt was introduced to the United States in the first decade of the twentieth century, influenced byÉlie Metchnikoff'sThe Prolongation of Life; Optimistic Studies(1908); it was available in tablet form for those with digestive intolerance and for home culturing.It was popularized byJohn Harvey Kelloggat theBattle Creek Sanitarium, where it was used both orally and inenemas,and later byArmenianimmigrants Sarkis and Rose Colombosian, who started "Colombo and Sons Creamery" inAndover, Massachusetts, in 1929.
Colombo Yogurt was originally delivered around New England in a horse-drawn wagon inscribed with the Armenian word "madzoon" which was later changed to "yogurt", theTurkish languagename of the product, as Turkish was thelingua francabetween immigrants of the variousNear Easternethnicities who were the main consumers at that time. Yogurt's popularity in the United States was enhanced in the 1950s and 1960s, when it was presented as ahealth foodby scientists like Hungarian-born bacteriologistStephen A. Gaymont.Plain yogurt still proved too sour for the American palate and in 1966 Colombo Yogurt sweetened the yogurt and added fruit preserves, creating "fruit on the bottom" style yogurt. This was successful and company sales soon exceeded $1 million per year.By the late 20th century, yogurt had become a common American food item and Colombo Yogurt was sold in 1993 toGeneral Mills, which discontinued the brand in 2010.
Yogurt (plain yogurt from whole milk) is 81% water, 9%protein, 5% fat, and 4%carbohydrates, including 4% sugars (table). A 100-gram amount provides 406 kilojoules (97 kcal) of dietary energy. As a proportion of theDaily Value(DV), a serving of yogurt is a rich source ofvitamin B12(31% DV) andriboflavin(23% DV), with moderate content of protein,phosphorus, andselenium(14 to 19% DV; table).
Tilde (~) represents missing or incomplete data. 
The above shows little difference exists between whole milk and yogurt made from whole milk with respect to the listed nutritional constituents.
Because it may contain live cultures, yogurt is often associated withprobiotics, which have been postulated as having positive effects onimmune,cardiovascularormetabolichealth.
As of the early 21st century, high-quality clinical evidence was insufficient to conclude that consuming yogurt lowers the risk of diseases or otherwise improves health.Meta-analysesfound that consuming 80 grams per day of low-fat yogurt was associated with a lower risk of developingtype 2 diabetesand a lower incidence ofhip fractureinpost-menopausalwomen.A 2021 review found acause-and-effectrelationship between yogurt consumption and improved lactose tolerance and digestion, and that potential associations exist between yogurt consumption and improving bone health, as well as lowering the risk of some diseases, including cancers andmetabolic syndrome.
Yogurt made withraw milkcan be contaminated with bacteria that can cause significant illness and even result in death, includingListeria,Cryptosporidium,Campylobacter,Brucella,Escherichia coliandSalmonella.Yogurts can also be contaminated withaflatoxin-producingAspergillus flavus,Aspergillus parasiticusandAspergillus nomius.
Contamination occurs in traditionally prepared yogurts more often than industrially processed ones, but may affect the latter as well if manufacturing and packaging practices are suboptimal.
When mold forms on yogurt it can not be scraped away. The consistency of yogurt allows the mold to penetrate deeply under the surface where it spreads.
Dahiis a yogurt from theIndian subcontinent, known for its characteristic taste and consistency. The worddahiseems to be derived from theSanskritworddadhi("sour milk"), one of the five elixirs, orpanchamrita, often used in Hindu ritual. Sweetened dahi (mishti doiormeethi dahi) is common in eastern parts of India, made by fermenting sweetened milk. While cow's milk is currently the primary ingredient for yogurt, goat and buffalo milk were widely used in the past, and valued for the fat content (seebuffalo curd).
Dadiahor dadih is a traditional WestSumatranyogurt made fromwater buffalomilk, fermented inbambootubes.Yogurt is common inNepal, where it is served as both an appetizer and dessert. Locally calleddahi, it is a part of the Nepali culture, used in local festivals, marriage ceremonies, parties, religious occasions, family gatherings, and so on. One Nepalese yogurt is calledjuju dhau, originating from the city ofBhaktapur. InTibet, yak milk (technically dri milk, as the word yak refers to the male animal) is made into yogurt (and butter and cheese) and consumed.
InNorthern Iran,Mâst Chekideis a variety ofkefiryogurt with a distinct sour taste. It is usually mixed with apesto-like water and fresh herb purée calleddelal. Common appetizers arespinachoreggplantborani,Mâst-o-Khiârwith cucumber, spring onions and herbs, andMâst-Musirwith wildshallots. In the summertime, yogurt and ice cubes are mixed together with cucumbers,raisins, salt, pepper and onions and topped with some croutons made of Persian traditional bread and served as a cold soup.Ashe-Mâstis a warmyogurt soupwith fresh herbs, spinach and lentils. Even the leftover water extracted whenstraining yogurtis cooked to make a sour cream sauce calledkashk, which is usually used as a topping on soups and stews.
Matsoniis aGeorgianyogurt in theCaucasusand Russia.Taratorandcacıkare cold soups made from yogurt during summertime in eastern Europe. They are made withayran,cucumbers,dill, salt,oliveoil, and optionally garlic and groundwalnuts.Tzatzikiin Greece andmilk saladin Bulgaria are thick yogurt-based salads similar to tarator.
Khyar w Laban(cucumber and yogurt salad) is a dish in Lebanon and Syria. Also, a wide variety of local Lebanese and Syrian dishes are cooked with yogurt like "Kibbi bi Laban"Rahmjoghurt, a creamy yogurt with much higher fat content (10%) than many yogurts offered in English-speaking countries.Dovga, a yogurt soup cooked with a variety of herbs and rice, is served warm in winter or refreshingly cold in summer.Jameed, yogurt salted and dried to preserve it, is consumed inJordan.Zabadiis the type of yogurt made in Egypt, usually from the milk of theEgyptian water buffalo. It is particularly associated withRamadanfasting, as it is thought to prevent thirst during all-day fasting.
To offset its naturalsourness, yogurt is also sold sweetened, sweetened and flavored or in containers with fruit or fruit jam on the bottom.The two styles of yogurt commonly found in the grocery store are set-style yogurt and Swiss-style yogurt. Set-style yogurt is poured into individual containers to set, while Swiss-style yogurt is stirred prior to packaging. Either may have fruit added to increase sweetness.
Lassiis a common Indian beverage made from stirred liquified yogurt that is either salted or sweetened with sugar commonly, less commonly honey and combined with fruit pulp to create flavored lassi.Consistency can vary widely, with urban and commercial lassis having uniform texture through being processed, whereas rural and rustic lassi has discernible curds or fruit pulp.
Large amounts of sugar – or othersweetenersfor low-energy yogurts – are often used in commercial yogurt.Some yogurts contain addedmodified starch,pectin(found naturally in fruit) orgelatinto create thickness and creaminess. This type of yogurt may be marketed under the name Swiss-style, although it is unrelated to conventional Swiss yogurt. Some yogurts, often called "cream line", are made with whole milk which has not been homogenized so the cream rises to the top. In many countries, sweetened, flavored yogurt is common, typically sold insingle-servingplastic cups.Common flavors may includevanilla,honey, andtoffee, and various fruits.In the early 21st century, yogurt flavors inspired by desserts, such as chocolate or cheesecake, became common.There is concern about thehealth effects of sweetened yogurtdue to its high sugar content,although research indicates that use of sugar in yogurt manufacturing has decreased since 2016 in response toWHOand government initiatives to combatobesity.
Strained yogurt has been strained through a filter, traditionally made ofmuslinand more recently of paper or non-muslin cloth. This removes thewhey, giving a much thicker consistency. Strained yogurt is made at home, especially if using skimmed milk which results in a thinner consistency.Yogurt that has been strained to filter or remove the whey is known asLabnehin Middle Eastern countries. It has a consistency between that of yogurt and cheese. It may be used forsandwichesin Middle Eastern countries. Olive oil, cucumber slices, olives, and various green herbs may be added. It can be thickened further and rolled into balls, preserved in olive oil, and fermented for a few more weeks. It is sometimes used with onions, meat, and nuts as a stuffing for a variety of pies orkibbehballs.
Some types of strained yogurts are boiled in open vats first, so that the liquid content is reduced. The East Indian dessert, a variation of traditional dahi calledmishti dahi, offers a thicker, more custard-like consistency, and is usually sweeter than western yogurts.In western Indian (Marathi and Gujarati) cuisine, strained yogurt is macerated with sugar and spices such as saffron, cardamom and nutmeg to make the dessert "shrikhand". Strained yogurt is also enjoyed in Greece and is the main component oftzatziki(from Turkish "cacık"), a well-known accompaniment togyrosandsouvlakipita sandwiches: it is a yogurt sauce or dip made with the addition of gratedcucumber,olive oil, salt and, optionally, mashed garlic.Srikhand, a dessert in India, is made from strained yogurt,saffron,cardamom,nutmegand sugar and sometimes fruits such asmangoorpineapple.
In North America, strained yogurt is commonly called "Greek yogurt". Powdered milk is sometimes added in lieu of straining to achieve thickness. In Britain as "Greek-style yogurt". In Britain the name "Greek" may only be applied to yogurt made in Greece.
Ayran,doogh("dawghe" inNeo-Aramaic) or dhallë is a yogurt-based, salty drink. It is made by mixing yogurt with water and (sometimes) salt.
Borhani(or burhani) is a spicy yogurt drink fromBangladesh. It is usually served with kacchibiryaniat weddings and special feasts. Key ingredients are yogurt blended with mint leaves (mentha),mustard seedsand black rock salt (Kala Namak). Ground roastedcumin, groundwhite pepper, greenchili pepperpaste and sugar are often added.
Lassiis a yogurt-based beverage that is usually slightly salty or sweet, and may be commercially flavored withrosewater,mangoor other fruit juice. Salty lassi is usually flavored with ground, roasted cumin andred chilies, and may be made withbuttermilk.
An unsweetened and unsalted yogurt drink usually called simplyjogurtis consumed withburekand other baked goods in theBalkans. Sweetened yogurt drinks are the usual form in Europe (including the UK) and the US, containing fruit and added sweeteners. These are typically called "drinkable yogurt". Also available are "yogurt smoothies", which contain a higher proportion of fruit and are more likesmoothies.
Yogurt production involves preparing warm milk to a temperature (30–45 °C (86–113 °F)) that will not kill the livemicroorganismsthat turn the milk into yogurt, inoculating certain bacteria (starter culture), usuallyStreptococcus thermophilusandLactobacillus bulgaricus, into the milk, and finally keeping it warm for several hours (4–12 hours).
Milk with a higher concentration of solids than normal milk may be used; the higher solids content produces a firmer yogurt. Solids can be increased by adding dried milk.The yogurt-making process provides two significant barriers topathogengrowth, heat and acidity (low pH). Both are necessary to ensure a safe product. Acidity alone has been questioned by recent outbreaks of food poisoning byE. coli O157:H7that is acid-tolerant.E. coli O157:H7is easily destroyed by pasteurization (heating); the initial heating of the milk kills pathogens as well as denaturing proteins.The microorganisms that turn milk into yogurt can tolerate higher temperatures than most pathogens, so that a suitable temperature not only encourages the formation of yogurt, but inhibits pathogenic microorganisms. Once the yogurt has formed it can, if desired, bestrainedto reduce the whey content and thicken it.
Two types of yogurt are supported by theCodex Alimentariusfor import and export.
Under USFood and Drug Administrationregulations, milk must be pasteurizedbeforeit is cultured, and may optionally be heat treated after culturing to increase shelf life.Most commercial yogurts in the United States are not heat treated after culturing, and contain live cultures.
Yogurt with live culturesis more beneficial than pasteurized yogurt for people with lactose malabsorption.
Lactose intoleranceis a condition in which people have symptoms due to the decreased ability to digest lactose, a sugar found in dairy products. In 2010, theEuropean Food Safety Authority(EFSA) determined that lactose intolerance can be alleviated by ingesting live yogurt cultures (lactobacilli) that are able to digest the lactose in other dairy products.The scientific review by EFSA enabled yogurt manufacturers to use ahealth claimon product labels, provided that the "yogurt should contain at least 10CFU live starter microorganisms (Lactobacillus delbrueckiisubsp.bulgaricusandStreptococcus thermophilus) per gram. The target population is individuals with lactose maldigestion".A 2021 review found that yogurt consumption could improve lactose tolerance and digestion.
A variety of plant-based yogurt alternatives appeared in the 2000s, usingsoy milk,rice milk, and nut milks such asalmond milkandcoconut milkfermented with cultures. These products may be suitable for people withlactose intoleranceor those who prefer plant-based foods such as vegetarians orvegans.Plant-based milkshave different structures and components thandairy milk. Though they can be used to make many products similar to those made from dairy, there are differences in taste and texture, and some consumers may feel that they lack the "delicate and smooth structure" of "conventional yogurts".Since plant-based milks do not containlactose(the food ofStreptococcus thermophilusandLactobacillus bulgaricus), plant-based products usually contain different bacterial strains than yogurt, such asLactobacillus casei,Lactobacillus rhamnosus, andBifidobacterium bifidum.Plant-based products also vary considerably in their nutrition and ingredients and may contain gums, stabilizers, high-intensity sweeteners, and artificial colors.
In Europe, companies may not market their plant-based products using the wordyogurtsince that term is reserved for products of animal origin only – perEuropean Union regulation1308/2013 and a 2017 ruling in theCourt of Justice of the European Union.Reaffirmed in 2021, per the USFDA'sStandard of Identityregulations, the wordyogurthas been reserved for a product made fromlactationand is a product of "milk-derived ingredients".