History

Yoghurt is traditionally believed to be an invention of the Turks of Central Asia, although there is evidence of cultured milk products in other cultures 4500 years ago. The earliest yoghurts were probably spontaneously fermented, perhaps by wild bacteria residing inside goatskin bags used for transportation.
     The word derives from the Turkish yogurt deriving from the verb yogurmak, which means “to blend”, a reference to how yoghurt is made. The letter g is silent between back vowels in Modern Turkish, but was formerly pronounced as a voiced velar fricative.
     Yoghurt remained primarily a food of India, Central Asia, Western Asia, South Eastern Europe and Central Europe until the 1900’s, when a Russian biologist named Ilya Ilyich Mechnikov theorized that heavy consumption of yoghurt was responsible for the unusually long lifespan of Bulgarian peasants. Believing lactobacillus to be essential for good health, Mechnikov worked to popularize yoghurt as a foodstuff throughout Europe. It fell to a Spanish entrepreneur named Isaac Carasso to industrialise the production of yoghurt. In 1919 he started a commercial yoghurt plant in Barcelona, naming the business Danone after his son – the group trades as Dannon in the US.
     Yoghurt with added fruit marmalade was invented (and patented) in 1933 indairy Radlicka Mlekarna in Prague. The original intention of this combination was to protect yoghurt better against decay.
     Yoghurt was first commercially produced and sold in the United States in 1929 by Armenian immigrants, Rose and Sarkis Colombosian, whose family business later became Colombo Yogurt.

Contents

Yoghurt making involves the introduction of specific “friendly” bacteria into preferably unpasteurised, unhomogenised milk (to maintain the healthy balance of bacteria and enzymes of milk in its unprocessed state) under very carefully controlled temperature and environmental conditions. The bacteria ingest the natural milk sugars and release lactic acid as a waste product; the increased acidity, in turn, causes the milk proteins to tangle into a solid mass, (curd, denature).
     The increased acidity (pH=405) also prevents the proliferation of other potentially pathogenic bacteria. Generally a culture includes two or more different bacteria for more complete fermentation.
     If the yoghurt is not heated to kill the bacteria after fermentation it is sold as containing “live active culture” (or just as “live” in some countries), which some believe to be nutritionally superior. In Spain, the yoghurt producers were divided among those who wanted to reserve the name yogur for live yoghurt and those who wanted to include pasteurized yoghurt under that label (mostly the Pascual Hermanos group). Pasteurised yoghurt has a shelf life of months and does not require refrigeration. Both sides submitted scientific studies claiming differences or their lack between both varieties. Eventually the Spanish government allowed the label yogur pasteurizado instead of the former postre lacteo (“dairy dessert”).
     Because live yoghurt culture contains enzymes that bread down lactose, some individuals who are otherwise lactose intolerant find that they can enjoy yoghurt without ill effects. Nutritionally, yoghurt is rich in protein as well as several B vitamins and essential minerals, and it is as low or high in fat as the mild it is made from.

Types of yoghurt

Bulgarian yoghurt is popular for its specific taste, aroma, and quality and is commonly consumed plain. The qualities are specific to the particular culture strains used in Bulgaria, Lactobacillus bulgaricus and Streptococcus thermophilus bacteria. Bulgarian yoghurt producers are taking steps to legally protect the trademark of Bulgarian yoghurt on the European market and distinguish it from other product types that do not contain live bacteria.
     Another kind of yoghurt known for characteristic taste and consistency is the dahi of the Indian subcontinent.
     Bulgarian yoghurt is often strained by hanging in a cloth for a few hours to reduce water content. The resulting yoghurt is creamier, richer and milder in taste because of increased fat content. Hanging overnight is sometimes employed to make concentrated yoghurt similar to cream cheese. Yoghurt is also used for preparation of Bulgarian milk salad (also known as Greek tzatziki sauce). Commercial versions of strained yoghurt are also made.
     Yoghurt is often sold sweetened and flavored, or with added fruit on the bottom (often referred toast fruit bottom, to offset its natural sourness. If the fruit is already stirred into the yoghurt, it is sometimes referred to as Swiss-style.
     Greek “full” yoghurt is made from milk that has been blended with cream to a fact content of exactly ten percent. Standard (5%), low-fat (2%) and non-fat (0%) versions are also made. It is often served with honey or fruit preserves as a dessert.
     The Greek traditional tzatziki sauce, used on a gyros sandwich, is made from yoghurt, cucumber, and garlic.
     Lassi is a yoghurt-based beverage, originally from India where two basic varieties are known: salty and sweet. Salty lassi is usually flavored with ground-roasted cumin and chile peppers; the sweet variety with rosewater and/or lemon, mango, or other fruit juice. Another yoghurt-based beverage, a salty drink called Ayran is quite popular in Turkey and Bulgaria. It is made my mixing yoghurt with water and adding salt. The same drink is known as tan in Armenia. A similar drink, Doogh, is popular in the Middle East between Lebanon and Iran; it differs from ayran by the addition of herbs (usually mint) and being carbonated.
     A cold soup (called tarator in Bulgaria and cacik in Turkey) made of yoghurt is popular in Turkey and Bulgaria in the summertime. It is made from Ayran, cucumbers, garlic and ground walnuts.
     Kefir is a fermented milk drink originating in the Caucasus. A related Central Asian-Mongolian drink made from mare’s milk is called kumis or, in Mongolia, airag. Some American dairies have offered a drink called “kefir” for many years (though lacking the carbonation and alcohol, and coming in fruit flavors), but bagan appearing (as of 2002) with names like “drinkable yoghurt” and “yogurt smoothie.”