Chillies, onions and garlic. Without them Thai food couldn’t exist. They are the Oscar-winning actors of our national cuisine. Bai kaprao, or holy basil, is a front-rank supporting cast player that turns up in innumerable important roles. If it were to disappear, Thai dishes with aggressive, spicy flavours would go along with it. But before discussing the roles that basil plays in the Thai kitchen, let’s take a look at the question of where it came from.
There is no clear evidence showing when basil arrived in Thailand. All we know is that it quickly became popular throughout Asia because of its medicinal properties and its virtues as a culinary herb.
It is easy to grow and proliferates quickly. Seeds appear in large numbers at the top of mature plants, and when they dry they fall out and are spread by the wind. Wherever they land there will soon be a new cluster of plants.
At spots in the forest where the sun shines through and the ground is not dense with vegetation, basil grows in with the grass. It has a bushy appearance and the leaves are small and very light green. Villagers call it kaprao pa, or wild basil, and value it as a medicinal herb good for cooking. When they go into the forest to hunt they take along rice, chillies and salt as provisions and find whatever meat they can. The tastiness of the food they prepare there owes a lot to wild basil.
There is no hard evidence to settle the questions of where the plant first appeared, in the forest or in people’s gardens. It is possible that seeds from cultivated plants blew into unfarmed areas and the plants established themselves there, where the plant adapted and changed.
No one can say for sure that this how it came about, however, and it is true that most of the plants in rural home gardens are red basil with red stems and small leaves that are green suffused with red on their upper surfaces but dark red underneath, while the wild basil is light green and is easy to distinguish from the cultivated variety. Another popular name for it is kaprao khao, or white basil. The intensity of the flavour and aroma of the two types of basil is about the same, but in rural areas people often bring the wild variety home to grow in the garden, as they believe that the red variety causes more of a sensation of heat when eaten.
In the provinces, every household will have a kitchen garden where staples such as chillies, aubergines, limes, kaffir limes, galangal and lemongrass are grown. Two more plants that can never be left out are the two commonest types of basil, kaprao and horapa. Chillies and basil in Thai cooking are like friends that tend to stick together in the dishes they season. Thais distinguish between different kinds of spicy heat. The hotness of chillies is sharper, and that of seasonings such as black pepper and basil is closer to thermal heat. Chillies contribute their kind of heat and basil give a different kind of warmth.
Bai kaprao is an important ingredient in many kinds of foods. In the basic version of the spicy curry made without coconut cream called kaeng pa, it gives the dish its special kind of heat. Pad prik bai kaprao dishes are stir-fries made with meat, chillies and bai kaprao. The first step in preparation is to chop the meat. It is a hard and fast rule that these dishes can only be made with chopped meat, which may be fish, frog, eel or any other kind with an appropriate taste and texture.
A different type of basil has joined the list of ingredients for pad bai kaprao dishes made with chopped meat. Bai kaprao khwai (shrubby basil) is used to make the beef version of the dish in the northern part of the Central region around Sukhothai, Phitsanulok and Phichit. It is used in the proportion three parts shrubby basil to seven parts wild or garden-grown basil. The result is a super-delicious variant of this popular dish. Shrubby basil is a close relative of bai kaprao, with a similar taste but stronger aroma and heating quality. Actually, this herb is known in other parts of Thailand, and in some localities in the Central region it is called yeera. Southerners call it bai ra while in the North it is known as kawmkaw or sawmkaw. The Isan name is eetoo.
Southerners like to add it to pad pet pla duk (a spicy catfish stir-fry) and khua kling (a fiery stir-fry made with minced meat). In the North it is cooked into the soup-like vegetable curry called kaeng khae or eaten raw with larb khua (another minced meat dish). In Isan it is an ingredient in another vegetable soup-like dish, kaeng awm, or is eaten raw.
In those parts of the Central region where it is called kaprao khwai, which literally means “water buffalo basil”, many believe that it gets its name from its tendency to flourish in the soft, porous soil near water buffalo pens where it is nourished by the animals’ manure.
Pad bai kaprao are made to order — fast food dishes all Thais know well. Thai restaurants almost always offer pad bai kaprao over rice topped with a fried egg. You can find it on every street in every town and city nationwide. Many people call it ahan sin khit (a no-brainer dish) because when they go into a food shop and don’t know what to order, or are in a part of the country where they are not familiar with the local cuisine, they order it automatically, without thinking. It’s easy, and anyone can make it.
But there used to be a problem with it, and it was an issue that troubled cooks and restaurant patrons for years. When either the wild or cultivated type of basil, with their tiny leaves, was fried, it shrunk down so much that on the plate it looked as if the cook had used it very sparingly.
Government agricultural departments found a solution by developing strains of both plants with big stems and leaves. They were given the name kaprao kaset, or “agriculture basil”, and found great favour with cooks because the basil in a serving of pad bai kaprao with a fried egg on top seemed to overflow the plate, making the dish look extra-appetising.
But the taste and fragrance of this new basil is only a pale shade of those of the smaller plants grown in kitchen gardens. People who cook pad bai kaprao for themselves at home prefer to seek out the original varieties of the plant. They can find it in the country, where villagers grow it for sale.
When they do locate some they don’t hesitate to buy, because it is certain to be part of the next meal they cook at home. Bai kaprao can never be missing from the kitchen for long. Just try to imagine Thai food without it.