There are over 504 varieties of basil, including many hybrids, so identifying those used in Laos can be confusing. Lao like to use small, young basil leaves whereas Thais seem to prefer larger, more mature basil.
Lao basil ຜັກອີຕູ່ pak i tou
The most common basil used for cooking in Laos, rather than for eating raw, is pak i tou. This basil has been identified definitively as Ocimum africanum.Lour. by Dr Somrun Suddee in a full revision of the tribe Ocimeae subtribe Ociminae (S. Suddee, personal communication, Jan 20, 2009; Suddee et al, 2005). This basil is most commonly put in Lao gaeng (soups) and aw (stews), such as gaeng bawt, aw lahm, pumpkin soup, fish moke and stuffed bamboo shoots. For soup, add at the end of cooking. The nutlets (seeds), which produce mucilage when wet, are used for making soup or a sweet dessert. In this website, Lao basil is referred to as pak i tou Lao to distinguish it from the variety in Laos called pak i tou Tai (sacred basil, holy basil or krapow in Thai) or pak boualapha (sweet basil, Thai basil or pak horapha in Thai). Pak i tou Lao has green leaves and stems and white flowers, but the leaves and calynx, which cups the flower, may have a purplish tinge. Raw pak i tou Lao does not have a strong taste; the flavour emerges upon cooking. The stems are slightly hairy. The basil may, but not necessarily will, have a slight citrus smell, but not taste. This basil species is of hybrid origin, derived from a cross between Ocimum americanum and Ocinimum basilicum (Paton & Putievsky, 1996). It freely hybridises with O. basilicum in cultivation; intermediates are not uncommon. In the Thai language, pak i tou Lao is one of the basil varieties called maenglak. A mild lemon basil or Western sweet basil may be substituted.
Holy basil, sacred basil Ocimum tenuiflorum, Ocimum sanctum ຜັກກະເຜົ່າ pak kapow, ຜັກສະເຜົ່າ bai sapow, ຜັກອີຕູ່ ໄທ pak i tou Tai
There is a big, bushy red variety with purple-pink flowers. It has a peppery clove or allspice taste. Freshly picked, it can be tongue-numbing. The green-stemmed variety with green leaves tinged with red is most commonly used in Laos. When put in soup, it is added at the end of cooking. It is used for Thai stir fries; pork with basil leaves is a common dish. In Lao dishes, it is stir fried with ginger or onion as a flavouring component. This basil is called bai krapow, or simply krapow, in Thai.
Sweet basil, Thai or sweet basil, Asian Ocimum basilicum ຜັກບົວລະພາ pak boualapha, pak boulaphe
This basil has an anise or licorice taste. It has purple stems and flower heads and long, narrow leaves. It is the most common basil accompanying lahp and Lao noodles. In Laos it is rarely used cooked. In Thailand, however, it frequently appears in green curries and other sauced dishes. This basil is called horapha in Thai. It is used as a medicine for dizziness. Pak boualapha (Lao) may also be used to identify Ocimum gratissimum called niam in Chiang Mai, Thailand.