Origin of the dish Kaeng Thepo is believed to have originated in
central Thailand during the early Rattanakosin period. The dish was originally made with pla thepo (
Pangasius larnaudii), a freshwater fish that was once common in Thai rivers. Over time, this fish became less available, and
pork belly was adopted as a substitute in many recipes, though the name of the dish was retained. The earliest references to Kaeng Thepo appear in 19th- and early 20th-century Thai cookbooks, including Patanu Krom Kan Tham Khong Khao Khong Wan (1898)
ปะทานุกรม การทำของคาวหวานอย่างฝรั่งแลสยาม and
Mae Khrua Hua Pa (1908–1909). These works described the dish as a variety of red curry that included fish,
water spinach,
tamarind, and
kaffir lime leaves as key ingredients. The dish was also noted in traditional literature such as royal poems, which praised its rich and savory flavor, suggesting that Kaeng Thepo had an established place in both household and ceremonial cooking during that era.
Development Over time, Kaeng Thepo was gradually adapted from its original fish-based recipe to include
pork belly as a more widely available substitute.
Coconut milk was later incorporated, giving the curry a creamier texture and balancing the spiciness of the red curry paste. In the early 20th century, printed cookbooks such as
Mae Khrua Hua Pa (1908–1909) provided variations of the recipe, showing how the dish was refined for both household and ceremonial cooking. During the mid-20th century, the dish became more commonly associated with central Thai home cooking rather than temple or royal cuisine. Alternative versions, including those with vegetarian substitutions and regional adaptations, also emerged to meet modern dietary preferences. These developments helped establish Kaeng Thepo as a recognized staple in Thai culinary tradition.
Spread within Thailand After becoming established as one of the traditional
coconut milk based curries of the
Central Thailand region, Kaeng thepho gradually spread into household cooking and was incorporated into the menus of everyday eateries in
Bangkok and other major urban centers. Food writers have noted that its classification within the group of sour coconut curries distinguishes it from typical Thai red curries and provides diners with a distinctive balance of sourness, sweetness, and saltiness. Kaeng thepho, though less popular than
Green curry or
Red curry, continues to appear in some traditional and family-style restaurants in Bangkok and other major cities, but is rarely found outside Central Thailand due to its specific ingredients and the cooking skills required.
Modern era In modern times, Kaeng thepho has adapted to contemporary lifestyles, with
pork belly often replacing the original fish, and commercial curry paste commonly used for convenience. Health-conscious variations reduce fat content, while restaurants emphasize lighter flavors and modern presentation. Despite these changes, it remains a three-flavor coconut curry balancing sourness, sweetness, and saltiness. ==Etymology and origins==