Does som tam taste the same wherever you eat it?
No. The chillies, seasonings and the way sweetness is added differ. If you are not used to fermented smells, ask first whether it uses pla ra.
Som Tam · ส้มตำ
If you fancy something crunchy and sour, try som tam. It is a salad made by shredding unripe papaya and pounding it with seasonings in a mortar. The papaya takes on sourness and heat, and goes well with sticky rice or grilled food. In Isan, some versions include a fermented fish seasoning, so if the fermented smell is unfamiliar, ask which kind of som tam it is when you order.

The crunch of papaya meets a sour and spicy dressing. Versions that use pla ra, a fermented fish seasoning, also bring a fermented aroma. Even the same som tam changes in flavour with the seasonings and chillies used.
If you want less heat, say so before it is made.
Som tam is a signature Isan dish eaten in many Thai cities. Even within Isan there are different kinds by area, so you can compare som tam much as you might compare regional specialities at home. On a trip to Khon Kaen, have it with sticky rice and other Isan dishes.
No. The chillies, seasonings and the way sweetness is added differ. If you are not used to fermented smells, ask first whether it uses pla ra.
Not necessarily. Some kinds use fish seasoning or shrimp. If you are vegetarian, ask whether the dressing and toppings are suitable as well as the papaya.
If you would like to read more about the food and the regions behind it, these sources are worth a look. Ingredients and cooking methods can vary from one cook to the next.
Sharing image credit: Vyacheslav Argenberg · CC BY 4.0