Thais employ a number of sauces and seasonings in food preparation and each plays its own role. The number of different labels and bottles can, however, be mind-boggling, so below is a brief description of the major sauces and their uses.
Light soy sauce (see ew khao): Also called white or light, this is your basic soy sauce, but with a Thai twist. Thai soy sauce has a mild and soft salty flavour not present in many other Asian soy sauces, hence I don’t think non-Thai varieties are appropriate for use in Thai recipes. My favourite brand is Healthy Boy, which comes in both large and small bottles. If you need to replace fish sauce in a recipe, use thin soy sauce.
Mushroom light soy sauce can be used interchangeably with plain light soy sauce. It’s a matter of preference.
Seasoning sauce: Golden Mountain brand is my favourite, but despite the difference in taste it’s interchangeable with Maggi seasoning (which is commonly found as a condiment in Thailand). Often considered the secret ingredient in Thai cooking, you’ll probably love this stuff so much you’ll need a new bottle before long. When seasoning sauce is called for in a recipe, assume it’s referring to Golden Mountain brand, which is ubiquitous across Thailand.
Things start to get confusing with dark/black soy sauce since there are many varieties, each with its own subtleties and varying levels of sweetness. I keep two on hand, one sweet bottle and one that contains molasses and is bolder and less sweet. Dark soy sauce is thicker than white or thin soy sauce, with a viscous, syrupy consistency. They are very different from dark soy sauces made in other Asian countries.
Dark/Black Soy Sauce (see ew dahm): Sometimes labelled as stir fry seasoning sauce (not to be confused with the seasoning sauce mentioned above), this is a strong and bold, salty and somewhat sweet soy sauce with a strong molasses flavour.
Dark Sweet Soy Sauce (see ew waan): Not dissimilar to Indonesian kecap manis, this syrupy sauce is thick, dark, and sweet. This is an essential ingredient in pad see ew and is often used as a dipping sauce.
Fermented soybean paste (Tao Jeow): Also known as yellow bean sauce and salted soy beans, there is nothing pretty about this much loved Thai condiment. There is also no doubt that it will heighten the flavour of food. Use in stir fries, rat na, and stir fried morning glory. If you absolutely cannot find it, use diluted brown miso paste as a substitute.
Sukiyaki sauce is served alongside sukiyaki (also called steamboat or hot pot), a communal dish where a pot of simmering broth at the table is used for cooking fresh ingredients such as dumplings and vegetables. Suki sauce was developed to accompany the Thai variation of the steamboat, and is suitable for pretty much vegetable you’d have along with your hot pot. Not a traditional preparation, but I also enjoy it mixed through noodles because it takes four seconds and sometimes I want four second noodles.
Thai sweet chilli sauce is a versatile condiment that can be used as a dipping sauce or marinade for just about anything. It is excellent with grilled foods or deep fried foods of joy like spring rolls.
Sriracha (pronounced see-rash-ah): Available in varying degrees of heat, this bright red garlicky chilli sauce also appears to be one of the most popular non ketchup table condiments in many countries outside of Thailand. The difference is that Thai versions are a little sweeter than those popularly available in North America and Europe (the Huy Fung rooster sauce does not taste like Thai sriracha). I love both and use them liberally.