Thai basil

Lore & Background

Thai basil is sturdy and compact, growing up to 45 cm, with shiny green, slightly serrated, narrow leaves and a sweet, anise-like scent with hints of licorice and slight spiciness. Its stem is purple and square, typical of the mint family, and its leaves are opposite and decussate. The inflorescence is a thyrse, purple in color, with pink flowers when open.

Thai basil is a variety of sweet basil (Ocimum basilicum), classified as O. basilicum var. thyrsiflora. It may be called chi neang vorng, anise basil, or licorice basil, but it differs from Western strains bearing those names. Occasionally it is called cinnamon basil, which is its literal Vietnamese name, though cinnamon basil typically refers to a separate cultivar. In Taiwan, it is known as káu-chàn-thah, meaning 'nine-storey pagoda'.

Three types of basil are commonly used in Thai cuisine: Thai basil (horapha), holy basil (kaphrao), and lemon basil (maenglak). Thai basil is widely used throughout Southeast Asia and plays a prominent role in Vietnamese cuisine, and is the cultivar most often used for Asian cooking in Western kitchens.

Reader's Guide

Thai basil is significant as a key ingredient in the cuisines of Southeast Asia, including Thai, Vietnamese, Lao, and Cambodian cuisines. Its leaves are a frequent ingredient in Thai green and red curries, and it is an important component of the Taiwanese dish sanbeiji (three-cup chicken). In Vietnamese cuisine, raw Thai basil leaves are served as an accompaniment to dishes such as phở (Southern style), bún bò Huế, and bánh xèo, allowing diners to season to taste.

Cultivated as a tender perennial typically grown as an annual, Thai basil requires fertile, well-draining soil with a pH of 6.5 to 7.5 and full sunlight. Its flowers should be pinched to prevent leaves from becoming bitter, and it can be repeatedly harvested to encourage regrowth. The plant's stability under high cooking temperatures makes it preferable to sweet basil in many cooked dishes.

Thai basil's distinctive anise- and licorice-like flavor, combined with its slight spiciness, sets it apart from other basil cultivars. Its purple stems and pink-purple flowers also make it visually distinct. The abundance of basil cultivars can lead to confusion, but Thai basil remains a staple in both traditional and Western adaptations of Asian cuisine.

Did You Know?

• Thai basil has a purple stem and square stem shape, typical of the mint family.
• Its scientific name is Ocimum basilicum var. thyrsiflora.
• In Taiwan, Thai basil is called káu-chàn-thah, meaning 'nine-storey pagoda'.
• Thai basil is more stable under high or extended cooking temperatures than sweet basil.