The prominent role that water has played in Thai life for centuries has driven chefs to develop techniques for cooking fish with the goal of eradicating bones and fishy smells, the major obstacles to making delicious dishes.
The know-how is the result of lifestyles in which people have depended heavily on canals and rivers for transport and their resources like fish which stand out as a staple Thai food.
From the biological standpoint, freshwater fish can be roughly classified into two groups -- species with scales and those without.
In the kitchen context, this means chefs require different methods of cooking.
Pla klet, a local broad term for fish with scales, has posed challenges for cooks as they contemplate how to remove, if not eradicate, the large number of fish bones in some species.
A quick way to judge the scale of the job ahead is that the larger the fish is, the greater number of bones are likely to be found.
A silver barb, locally known as pla taphian, is often used to make popular dishes because of its pleasant smell when cooked. Some chefs do not remove or eradicate their bones. They simply "transform" them.
Cooks usually made narrow cuts along the fish's body. This allows them to easily cut the soft bones fixed firmly inside its meat. The next step is to fry the fish until the bones turn crispy.
The other way to deal with the bones is boiling. Pla taphian can be boiled with fish and tamarind sauces, together with sugar. This process usually takes several hours to make sure the bones "dissolve" in the meat.
Thais call this dish pla tom khem, or salted fish soup.
Another fish in this group are Jullien's Golder Price Carp (pla yisok) and Soldier River Barb (pla trakok). Like pla taphian, the two species contain fats that give off an attractive smell when cooked. But because of their large size, it is more difficult to cut and fry their bones.
Yet cooking them is considered easier when the chefs' skills have been tested with a larger species -- Hampala Barb (pla krasup). This is a predator fish mostly found in large reservoirs.
Pla krasup is not usually fished for cooking but are fished for the sheer challenge of landing such a large species.
Another fish in this group -- Snake fish (pla chon) -- also presents a high level of difficulty, but it is the blood, not bones, which are the problem here. Its blood has a very fishy smell.
Cooks have to make sure pla chon is cleaned thoroughly as small amount of blood unwashed can turn a popular pla chon dish into a disaster.
They must also know how to extract its delicious taste by cooking it in sour spicy soup, known as tom yam, and stir-frying it with celery, which is famous for its strong pungent smell.
A fishy smell is also a problem with the other group of fish -- those without scales.
Best known among these is the catfish, pla duk, which is popular but very smelly. Many techniques are used to overcome this notorious characteristic. One is stir-frying plau duk with chilies and mixing them with spices such as finger roots, kaffir lime leaves or cumin seeds.
Some cooks also add an additional step. They first fry the fish and then stir-fry it with various spices to make praduk krop phat plik gaeng (stir-fired crispy catfish with spices).
Another species is the striped catfish, pla sawai, which also has a strong smell. This can be solved by removing its fat, which emits a stench, along its backbone before cooking. The fish is usually mixed with fermented bamboo shoots to make a soup with a hot taste.
However, people nowadays tend not to eat pla sawai because they are often spotted in canals or rivers in front of temples. The fish appear to be so-called "temple's animals" and Buddhists consequently refrain from killing them.
Instead of being cooked to please the tongues, pla sawai plays a new role in satisfying people's minds. Many Thais would rather sprinkle pieces of bread in the river to feed pla sawai as an act of merit-making, which seems to be a new water culture-based activity.
But as for other fish destined for the kitchen, the goals of cooking these remain the same --removing bones and getting rid of the smell.
One technique to "overcome" these obstacles for people who are unfamiliar with culinary arts is to do nothing. They just go to the market and simply ask vendors which fish are the least smelly and do not have many bones.
Choosing the most convenient way of cooking is recommended as the underlying goal behind all cooking methods is to be happy with the eating.
