A bowl of yogurt garnished with fruit and herb
|Main ingredient(s)||Milk, bacteria|
|Nutritional value per 100 g (3.5 oz)|
|Energy||257 kJ (61 kcal)|
|- Sugars||4.7 g (*)|
|- saturated||2.1 g|
|- monounsaturated||0.9 g|
|Vitamin A equiv.||27 μg (3%)|
|Riboflavin (vit. B2)||0.14 mg (12%)|
|Calcium||121 mg (12%)|
|(*) Lactose content diminishes during storage.
Percentages are relative to
US recommendations for adults.
Source: USDA Nutrient Database
Yogurt or yoghurt or yoghourt (// or //; other spellings listed below) is a fermented milk product (soy milk, nut milks such as almond milk, and coconut milk can also be used) produced by bacterial fermentation of milk. The bacteria used to make yogurt are known as "yogurt cultures". Fermentation of lactose by these bacteria produces lactic acid, which acts on milk protein to give yogurt its texture and its characteristic tang.
Worldwide, cow's milk, the protein of which mainly comprises casein, is most commonly used to make yogurt, but milk from water buffalo, goats, ewes, mares, camels, and yaks is also used in various parts of the world.
Dairy yogurt is produced using a culture of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus bacteria. In addition, other lactobacilli and bifidobacteria are also sometimes added during or after culturing yogurt. Some countries require yogurt to contain a certain amount of colony-forming units of microorganisms.
In Western culture, the milk is first heated to about 80 °C (176 °F) to kill any undesirable bacteria and to denature the milk proteins so that they set together rather than form curds. In some places, such as parts of India, curds are a desired component and milk is not pasteurized. The milk is then cooled to about 45 °C (112 °F). The bacterial culture is added, and the temperature is maintained for 4 to 7 hours to allow fermentation.
Etymology and spelling
The word is derived from Turkish: yoğurt, and is related to the obsolete verb yoğmak "to be curdled or coagulated; to thicken". The letter ğ was traditionally rendered as "gh" in transliterations of Turkish prior to 1928. In older Turkish, the letter denoted a voiced velar fricative /ɣ/, but this sound is elided between back vowels in modern Turkish, in which the word is pronounced [joˈuɾt].
In English, there are several variations of the spelling of the word, including yogurt, yoghurt, yoghourt, yogourt, yaghourt, yahourth, yoghurd, joghourt, and jogourt. In the United Kingdom and Australia, yogurt and yoghurt are both current, yogurt being more common while yogurt is used by the Australian and British dairy councils, and yoghourt is an uncommon alternative. In the United States, yogurt is the usual spelling and yoghurt a minor variant. In New Zealand, yoghurt is preferred by the New Zealand Oxford Dictionary. In Canada, yogurt is most common among English speakers, but many brands use yogourt, since it is an acceptable spelling in both English and French, the official languages of Canada.
Whatever the spelling, the word is usually pronounced with a short o // in England, with a long o // in Scotland, North America, Australia, Ireland and South Africa, and with either a long or short o in New Zealand.
The origins of yogurt are unknown. Analysis of the L. delbrueckii subsp. bulgaricus genome indicates that the bacteria may have originated on the surface of a plant. Milk may have become spontaneously and unintentionally infected through contact with plants, or bacteria may have been transferred via the udder of domestic milk-producing animals.
In ancient Indian records, the combination of yogurt and honey is called "the food of the gods". Persian traditions hold that "Abraham owed his fecundity and longevity to the regular ingestion of yogurt".
The oldest writings mentioning yogurt are attributed to Pliny 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 medieval Turks is recorded in the books Diwan Lughat al-Turk by Mahmud Kashgari and Kutadgu Bilig by Yusuf Has Hajib written 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 spontaneously fermented by wild bacteria in goat skin bags.
Another early account of a European encounter with yogurt occurs in French clinical history: Francis I suffered from a severe diarrhea which no French doctor could cure. His ally Suleiman the Magnificent sent a doctor, who allegedly cured the patient with yogurt. Being grateful, the French king spread around the information about the food which had cured him.
Until the 1900s, yogurt was a staple in diets of people in the Russian Empire (and especially Central Asia and the Caucasus), Western Asia, South Eastern Europe/Balkans, Central Europe, and India. Stamen Grigorov (1878–1945), a Bulgarian student of medicine in Geneva, first examined the microflora of the Bulgarian yogurt. In 1905, he described it as consisting of a spherical and a rod-like lactic acid bacteria. In 1907, the rod-like bacterium was called Bacillus bulgaricus (now Lactobacillus delbrueckii subsp. bulgaricus). The Russian Nobel laureate biologist Ilya Ilyich Mechnikov (also seen as Élie Metchnikoff), from the Institut Pasteur in Paris, was influenced by Grigorov's work and hypothesized that regular consumption of yogurt was responsible for the unusually long lifespans of Bulgarian peasants. Believing Lactobacillus to be essential for good health, Mechnikov worked to popularize yogurt as a foodstuff throughout Europe.
Isaac Carasso industrialized the production of yogurt. In 1919, Carasso, who was from Ottoman Salonika, started a small yogurt business in Barcelona, Spain, and named the business Danone ("little Daniel") after his son. The brand later expanded to the United States under an Americanized version of the name: Dannon.
Yogurt was first introduced to the United States in the first decade of the twentieth century, influenced by Élie Metchnikoff's The Prolongation of Life; Optimistic Studies (1908); it was available in tablet form for those with digestive intolerance and for home culturing. It was popularized by John Harvey Kellogg at the Battle Creek Sanitarium, where it was used both orally and in enemas, and later by Armenian immigrants Sarkis and Rose Colombosian, who started "Colombo and Sons Creamery" in Andover, 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", the Turkish name of the product, as Turkish was the lingua franca between immigrants of the various Near Eastern ethnicities 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 a health food. By the late 20th century, yogurt had become a common American food item and Colombo Yogurt was sold in 1993 to General Mills, which discontinued the brand in 2010.
Nutritional value and health benefits
Yogurt is nutritionally rich in protein, calcium, riboflavin, vitamin B6 and vitamin B12. It has nutritional benefits beyond those of milk. Lactose-intolerant individuals can sometimes tolerate yogurt better than other dairy products, because the lactose in the milk is converted to glucose and galactose, and partially fermented to lactic acid, by the bacterial culture.
Yogurt containing live cultures has been found effective in a randomized trial at preventing antibiotic-associated diarrhea. Yogurt contains varying amounts of fat. There is non-fat (0% fat), low-fat (usually 2% fat) and plain or whole milk yogurt (4% fat). A study published in the International Journal of Obesity (11 January 2005) also found that the consumption of low-fat yogurt can promote weight loss.
Yogurt is a valuable health food for both infants and elderly persons. For children, it is a balanced source of protein, fats, carbohydrates, and minerals. For senior citizens, who usually have more sensitive colons or whose intestines have run out of lactose, yogurt is also a valuable food. Elderly intestines showed declining levels of bifidus bacteria, which allow the growth of toxin-producing and, perhaps, cancer-causing bacteria. Yogurt may help prevent osteoporosis, reduce the risk of high blood pressure. Yogurt with active cultures helps the gut, may discourage vaginal infections, and may help one feel fuller.
Varieties and presentation
Da-hi is a yogurt of the Indian subcontinent, known for its characteristic taste and consistency. The word da-hi seems to be derived from the Sanskrit word dadhi, one of the five elixirs, or panchamrita, often used in Hindu ritual. Dahi also holds cultural symbolism in many homes in the Mithilanchal region of Bihar. It is found in different flavors, two of which are very widely known: sour yogurt (tauk doi) and sweet yogurt (meesti or podi doi). In India and Pakistan, it is often used in cosmetics mixed with turmeric and honey. Sour yogurt,खट्टा दही, (not "खट्टी दही", since in Hindi the word for yogurt has a masculine grammatical gender) is also used as a hair conditioner by women in many parts of India and Pakistan. Dahi is also known as Mosaru (Kannada), Thayir (Tamil), Thayiru (Malayalam), doi (Assamese, Bengali), dohi (Oriya), perugu (Telugu), Qәzana a pәәner (Pashto) and Dhahi or Dhaunro (Sindhi ڏهي، ڌونرو)
Yogurt is popular in Nepal, where it is served as both an appetizer and dessert. Locally called dahi (दही), it is a part of the Nepali culture, used in local festivals, marriage ceremonies, parties, religious occasions, family gatherings, and so on. The most famous type of Nepalese yogurt is called juju dhau, originating from the city of Bhaktapur. In Tibet, yak milk (technically dri milk, as the word yak refers to the male animal) is made into yogurt (and butter and cheese) and consumed.
In Northern Iran, Mâst Chekide is a variety of kefir yogurt with a distinct sour taste. It is usually mixed with a pesto-like water and fresh herb purée called delal. Yogurt is a side dish to all Iranian meals. The most popular appetizers are spinach or eggplant borani, Mâst-o-Khiâr with cucumber, spring onions and herbs, and Mâst-Musir with wild shallots. 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-Mâst is a warm yogurt soup with fresh herbs, spinach and lentils. Even the leftover water extracted when straining yogurt is cooked to make a sour cream sauce called kashk, which is usually used as a topping on soups and stews.
Matsoni is a Georgian yogurt popular in the Caucasus and Russia. It is used in a wide variety of Georgian dishes and is believed to have contributed to the high life expectancy and longevity in the country. Dannon used this theory in their 1978 TV advertisement called In Soviet Georgia where shots of elderly Georgian farmers were interspersed with an off-camera announcer intoning, "In Soviet Georgia, where they eat a lot of yogurt, a lot of people live past 100." Matsoni is also popular in Japan under the name Caspian Sea Yogurt (カスピ海ヨーグルト).
Tarator and Cacık are popular cold soups made from yogurt, popular during summertime in Albania, Azerbaijan (known as Dogramac), Bulgaria, Republic of Macedonia, Serbia and Turkey. They are made with ayran, cucumbers, dill, salt, olive oil, and optionally garlic and ground walnuts. Tzatziki in Greece and milk salad in Bulgaria are thick yogurt-based salads similar to tarator.
Khyar w Laban (cucumber and yogurt salad) is a popular dish in Lebanon and Syria. Also, a wide variety of local Lebanese and Syrian dishes are cooked with yogurt like "Kibbi bi Laban", etc.
Dovga, a yogurt soup cooked with a variety of herbs and rice is popular in Azerbaijan, often served warm in winter or refreshingly cold in summer.
Cream-top yogurt is yogurt made with unhomogenized milk. A layer of cream rises to the top, forming a rich yogurt cream. Cream-top yogurt was first made commercially popular in the United States by Brown Cow of Newfield, New York, bucking the trend toward low- and non-fat yogurts.
Zabadi is the type of yogurt made in Egypt, usually from the milk of the Egyptian water buffalo. It is particularly associated with Ramadan fasting, as it is thought to prevent thirst during all-day fasting.
Raita is a yogurt-based South Asian/Indian condiment, used as a side dish. The yogurt is seasoned with cilantro (coriander), cumin, mint, cayenne pepper, and other herbs and spices. Vegetables such as cucumber and onions are mixed in, and the mixture is served chilled. Raita has a cooling effect on the palate which makes it a good foil for spicy Indian and Pakistani dishes.
Dahi is a Sindhi-curd, popular in India and Pakistan. People drink dahi along with food at intervals, to help digestion and make food more delicious. In some places, dahi is also served with plain rice.
Sweetened and flavored yogurt
To offset its natural sourness, yogurt is also sold sweetened, 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 type yogurt and Swiss style yogurt. Set type yogurt is when the yogurt is packaged with the fruit on the bottom of the cup and the yogurt on top. Swiss style yogurt is when the fruit is blended into the yogurt prior to packaging.
Large amounts of sugar – or other sweeteners for low-calorie yogurts – are often used in commercial yogurt. Some yogurts contain added starch, pectin (found naturally in fruit), and/or gelatin to create thickness and creaminess artificially at lower cost. This type of yogurt is also marketed under the name Swiss-style, although it is unrelated to the way yogurt is eaten in Switzerland. Some yogurts, often called "cream line," are made with whole milk which has not been homogenized so the cream rises to the top. Fruit jam is used instead of raw fruit pieces in fruit yogurts to allow storage for weeks.
In the UK, Ireland, France and USA, sweetened, flavored yogurt is the most popular type, typically sold in single-serving plastic cups. Common flavors include vanilla, honey, and toffee, and fruit such as strawberry, cherry, blueberry, blackberry, raspberry, mango and peach. In the early twenty-first century yogurt flavors inspired by desserts, such as chocolate or cheesecake, have been available.
Strained yogurt is yogurt which has been strained through a paper or cloth filter, traditionally made of muslin., to remove the whey, giving a much thicker consistency and a distinctive, slightly tangy taste. Strained yogurt is becoming more popular with those who make yogurt at home, especially if using skim milk which results in a thinner consistency. Once yogurt is made and refrigerated overnight, it is poured in a muslin or cheesecloth bag and hung in the coolest place in the house, with a tub placed underneath to collect the dripping whey. In cold weather a single day (or night) of straining is sufficient. In higher ambient temperatures yogurt will spoil rapidly, therefore it had best be actively squeezed or strained until about a third or more of its initial weight has run off. The remainder is now strained and is refrigerated again.
Labneh is a strained yogurt used for sandwiches popular in Arab 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 or kebbeh (كبة) balls.
Some types of strained yogurts are boiled in open vats first, so that the liquid content is reduced. The popular East Indian dessert, a variation of traditional dahi called mishti dahi, offers a thicker, more custard-like consistency, and is usually sweeter than western yogurts.
Strained yogurt is also enjoyed in Greece and is the main component of tzatziki (from Turkish "cacık"), a well-known accompaniment to gyros and souvlaki pita sandwiches: it is a yogurt sauce or dip made with the addition of grated cucumber, olive oil, salt and, optionally, mashed garlic.
Dugh ("dawghe" in Neo-Aramaic), ayran or dhallë is a yogurt-based, salty drink popular in Iran, Albania, Bulgaria, Turkey, Azerbaijan, Afghanistan, Pakistan, Bangladesh, the Republic of Macedonia, Kazakhstan and Kyrgyzstan. It is made by mixing yogurt with water and (sometimes) salt. The same drink is known as doogh in Iran; tan in Armenia; laban ayran in Syria and Lebanon; shenina in Iraq and Jordan; laban arbil in Iraq; majjiga (Telugu), majjige (Kannada), and moru (Tamil and Malayalam) in South India; namkeen lassi in Punjab and all over Pakistan. A similar drink, doogh, is popular in the Middle East between Lebanon, Iran, and Iraq; it differs from ayran by the addition of herbs, usually mint, and is sometimes carbonated, commonly with carbonated water.
Borhani (or Burhani) is a spicy yogurt drink popular in Bangladesh and parts of Bengal. It is usually served with kacchi biryani at weddings and special feasts. Key ingredients are yogurt blended with mint leaves (mentha), mustard seeds and black rock salt (Kala Namak). Ground roasted cumin, ground white pepper, green chili pepper paste and sugar are often added.
Lassi (Hindi: लस्सी, Urdu: لسی) is a yogurt-based beverage originally from the Indian subcontinent that is usually slightly salty or sweet. Lassi is a staple in Punjab. In some parts of the subcontinent, the sweet version may be commercially flavored with rosewater, mango or other fruit juice to create a very different drink. Salty lassi is usually flavored with ground, roasted cumin and red chilies; this salty variation may also use buttermilk, and in India is interchangeably called ghol (Bengal), mattha (North India), majjiga (Andhra Pradesh), moru (Tamil Nadu and Kerala), Dahi paani (Odisha), tak (Maharashtra), or chaas (Gujarat). Lassi is very widely drunk in India, Pakistan, and Bangladesh. Mango Lassi is a popular drink at Indian restaurants in US.
In Bosnia and Herzegovina, Croatia, the Republic of Macedonia, Montenegro, Serbia, and Slovenia, an unsweetened and unsalted yogurt drink usually called simply jogurt is a popular accompaniment to burek and other bakery products.
Sweetened yogurt drinks are the usual form in Europe (including the UK) and the US, containing fruit and added sweeteners. These are typically called "drinking / drinkable yogurt", such as Yop and BioBest Smoothie.
Also available are "yogurt smoothies", which contain a higher proportion of fruit and are more like smoothies. In Ecuador, yogurt smoothies flavored with native fruit are served with pan de yuca as a common type of fast food.
Also in Turkey, yogurt-soup or Yayla Çorbası is a popular way of consuming yogurt. The soup is a mix of yogurt, rice, flour and dried mint.
Since at least 1977 yogurt has been made from soymilk. As of Sept. 2012 at least 174 commercial soy yogurts, both spoonable and drinkable, have been launched worldwide, including 83 in the USA and 58 in Europe
Making yogurt at home
Yogurt is made by inoculating certain bacteria (starter culture), usually Streptococcus thermophilus and Lactobacillus bulgaricus, into milk. After inoculation, the milk is incubated at approximately 110°F ± 5°F until firm; the milk is coagulated by bacteria-produced lactic acid.
The milk used to make yogurt contains a higher concentration of solids than normal milk. By increasing the solids content of the milk, a firm, rather than soft, end product results. Addition of nonfat dry milk (NFDM) is the easiest at-home method for doing this. Another method is using scalded milk: heating milk near boiling, then letting it cool down. The process denaturates whey proteins, which makes yogurt thicker.
The yogurt making process provides two significant barriers to pathogen growth: (a) heat and (b) acidity (low pH). Both are necessary to ensure a safe product. Acidity alone has been questioned by recent outbreaks of food poisoning by E. coli O157:H7 that is acid-tolerant. E. coli O157:H7 is easily destroyed by pasteurization (heating). Therefore, always pasteurize milk or use commercially pasteurized milk to make yogurt.
This initial process is the first step in making strained yogurt as mentioned above by eliminating some of the liquid whey. Koji (Aspergillus oryzae) starter Kits and kefir grains are also used in the home for making a wide variety of fermented dairy, soy and wheat products.
Other fermented dairy products
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