Thai soup
Tom yum or tom yam (, ;[3] Thai: ต้มยำ, RTGS: tom yam [tôm jām] ⓘ) is a family of hot and sour Thai soups. It is a soup that normally includes shrimp. The strong hot and sour flavors makes it very popular in Thai cuisine.[4] The name "tom yam" is composed of two Thai words. Tom refers to the boiling process, while yam means 'mixed'.
Historian Giles Milton contends that the origins of Tom Yum can be traced back to India, where there is a variation of hot and sour shrimp soup known as "sour prawn soup."[5]
Preparation
The soup base depends on the exact sub-type but is generally water, coconut milk, or chicken or other broth.[6]
Various aromatic ingredients are sliced, roughly pounded, and simmered to extract their flavor. These include fresh ingredients such as lemongrass, kaffir lime leaves, galangal, chilis, shallots, and garlic. For shrimp-based soups, shrimp shells and heads may also be simmered, to extract their flavor. These ingredients are often then removed as their flavor is now extracted and many aren't edible. However they may be left in, as an aid to presentation.[6]
Alternatively, commercial tom yum paste may be used. This is made by crushing all the herb ingredients and stir frying in oil, then adding seasoning and other preservative ingredients. The paste is bottled or packaged and sold around the world.
Vegetables are then added, such as onion and tomato. In modern popular versions the soup may also contain mushrooms—usually straw mushrooms or oyster mushrooms.[6]
Various meats are added next, commonly fish, shrimp, mixed seafood, pork, or chicken.[6]
When the meat is cooked, final flavorings whose taste is destroyed by heat, such as fish sauce and lime juice, are added. For most varieties a paste called nam phrik phao (Thai: น้ำพริกเผา) is also added, made from shrimp, chilis, shallots, and garlic.[7] This imparts sweet, salty, and spicy tastes.[6]
Yet other ingredients may also be used, depending on the exact variety of tom yam, such as evaporated milk.[6]
The soup is often topped with a generous sprinkling of fresh chopped coriander leaves, and may be served over a serving of rice.[6]
Other spicy and sour soups
Less well known outside Thailand is tom khlong (ต้มโคล้ง), a spicy sour soup where the sourness does not derive from lime juice but through the use of tamarind.[16] Tom som (Thai: ต้มส้ม) are soups that are also very similar to tom yum but most often do not contain lemongrass or kaffir lime leaves. Depending on the type of tom som, the acidity can be derived from lime juice or from the use of tamarind.[17][18]
Outside Thailand
Malaysia
Tom yum, locally spelled as tomyam, is very well-received among Malaysians since its introduction around the 1980s.[19][20] The cuisine is now considered a must-have on most restaurant menus in Malaysia, especially the peninsular states.[20] As of 2018, the popularity of tom yum and other Thai dishes had brought employment to at least 120,000 south Thai cooks, working restaurants mainly in Selangor state and the capital city of Kuala Lumpur, and owning 5000 to 6000 Thai restaurants throughout the country.[20][19]
