Thai basil is a type of basil native to Southeast Asia that has been cultivated to provide distinctive traits. Widely used throughout Southeast Asia, its flavour, described as anise- and licorice-like and slightly spicy, is more stable under high or extended cooking temperatures than that of sweet basil. Thai basil has small, narrow leaves, purple stems, and pink-purple flowers.
Taxonomy and Naming
Sweet basil (Ocimum basilicum) has multiple cultivars, of which Thai basil, O. basilicum var. thyrsiflora, is one variety. Thai basil itself has multiple cultivars. One cultivar commonly grown in the United States is ‘Siam Queen’. Thai basil may sometimes be called anise basil or licorice basil, in reference to its anise- and licorice-like scent and taste, but it is different from the Western strains bearing these same names. Occasionally, Thai basil may also be called Cinnamon Basil, which is also its literal name in Vietnamese, but cinnamon basil typically refers to a separate cultivar of basil. The genus name Ocimum is derived from the Greek word meaning “to smell”, which is appropriate for most members of the plant family Lamiaceae, also known as the mint family. With over 40 cultivars of basil, this abundance of flavours, aromas, and colours leads to confusion when identifying specific cultivars.
Three types of basil are commonly used in Thai cuisine.
- First, Thai basil, or horapha (Thai: โหระพา), is widely used throughout Southeast Asia and plays a prominent role in Vietnamese cuisine. It is also the cultivar most often used for Asian cooking in Western kitchens.
- Second, Holy Basil (O. tenuiflorum), or kaphrao (Thai: กะเพรา), which has a spicy, peppery, clove-like taste, may be the basil Thai people love most. Holy basil is also known as Thai holy basil or by its Indian name, tulasi or tulsi; it is widely used in India for culinary, medicinal, and religious purposes.
- Finally, Lemon Basil (O. × citriodorum), or maenglak (Thai: แมงลัก), as its name implies, has undertones of lemon in both scent and taste. Lemon basil is the least commonly used type of basil in Thailand. It is also known as Thai lemon basil, in contradistinction to Mrs. Burns Lemon Basil, another cultivar of basil.
Thai basil is sturdy and compact, growing up to 45 cm (1.48 ft), and has shiny green, slightly serrated, narrow leaves with a sweet, anise-like scent and hints of licorice, along with a slight spiciness lacking in sweet basil. Thai basil has a purple stem, and like other plants in the mint family, the stem is square. Its leaves are opposite and decussate. As implied by its scientific name, Thai basil flowers in the form of a thyrse. The inflorescence is purple, and the flowers when open are pink.
Thai basil is a tender perennial but is typically grown as an annual. As a tropical plant, Thai basil is hardy only in very warm climates where there is no chance of frost. Thai basil, which can be grown from seed or cuttings, requires fertile, well-draining soil with a pH ranging from 6.5 to 7.5 and 6 to 8 hours of full sunlight per day. The flowers should be pinched to prevent the leaves from becoming bitter. Thai basil can be repeatedly harvested by taking a few leaves at a time and should be harvested periodically to encourage regrowth.
- Thai basil is widely used in the cuisines of Southeast Asia, including Thai, Vietnamese, Lao, and Cambodian cuisines.
- Thai basil leaves are a frequent ingredient in Thai green and red curries, though in Thailand the basil used in drunken noodles and many chicken, pork, and seafood dishes is holy basil.
- In the West, however, such dishes typically contain Thai basil instead, which is much more readily available than holy basil.
- Thai basil is also an important ingredient in the very popular Taiwanese dish San Bei Ji ( Three Cup Chicken).
- Used as a condiment, a plate of raw Thai basil leaves is often served as an accompaniment to many Vietnamese dishes, such as phở, bún bò Huế, or bánh xèo, so that each person can season to taste with the anise-flavoured leaves.
- If your recipe calls for Thai or Asian basil you can substitute with the common Mediterranean variety with similar but not the exact taste results.
- If you want an entirely different flavour substitute mint.
Where To Buy
- Fresh Thai Basil can be purchased at most Asian markets.
- If you don’t live in an area where you have access to Asian markets you may want to grow your own. You can purchase live plants and seeds online.
How to Store
- Store basil for up to 1 week in the refrigerator.
- Leave it in its original plastic container or rinse the leaves, roll them up in paper towels, and place them in a resealable plastic bag for up to about 4 days.
- Sometimes basil will keep longer if you trim the stems and put them in a glass of water-like you would with fresh flowers, then put a plastic bag over them and refrigerate.
- Medicinally basil is used both as an antidepressant and an antiseptic.
- Leaves can be rubbed on the skin to relive itching from insect bites.
- The leaves are also made into a concoction with honey and used for cough syrup.
- The essential oil extracted from the leaves can be used as an insect repellent or massage oil to aid in depression and anxiety.