There are all kinds of soups made in Thailand and the one thing almost all have in common is that intriguing flavor that is simultaneously sour, salty and spicy. Thais call this flavor “yum.” The ingredients that are give these bold flavors are the basics of the Thai kitchen.

Sour flavors are derived from limes and sour tamarind. Limes are always used to flavor soups because their sourness has a slightly sweet finish. Lemons and tamarind tend to be slightly more bitter in the finish and are more often used in stir-fry.

Salt is rarely used; instead there is fish sauce (nam pla), a liquid made from salted fermented fish.

Spiciness comes from small, skinny Thai chiles.