Just like Scotch and Irish whiskeys, bourbon must comply with a number of rules to be legally considered a bourbon:
• It must be made in the USA, though almost all famous distillers are in the state of Kentucky. In fact, the name comes from Bourbon County, Kentucky.
• It must be made largely with Indian corn. Some small percentage of barley, wheat or rye is permissible.
• The alcohol must be aged in new oak barrels that have been charred on the inside. For a bourbon to be considered straight, no colorings or flavors should have been added, and it must have been aged for at least two years.
• Bourbons labeled blended have added colorings and flavors.

Here are some bottles readily available in Bangkok.

Maker’s Mark
B1,299 at Tops

Pretty standard at bars in Bangkok, Marker’s Mark is a relatively cheap go-to option. It’s double-distilled in copper pots and, instead of rye, uses red winter wheat in the grain mix, making it less harsh and spicy. Instead it’s got a lot of fruit going on, along with ginger and oak.

Jim Beam Black
B999 at Tops
Aged a whopping eight years, this whiskey has got a lot of body and big caramel, vanilla and oak flavors. Decent for sipping, though you might want to dilute it with a splash of water or a large ice cube.

Heaven Hill
B565 at Emporium Wine Cellar
Cheap and still reasonably smooth, Heaven Hill has a decent amount of rye in the blend and a sweet, caramel finish.

Woodford Reserve
B2,100 at Emporium Wine Cellar
The official whisky of the famous Kentucky Derby, Woodford Reserve touts itself as craft bourbon. They use limestone water, a very high percentage of rye in their grain mix (18%) and copper pots imported from Scotland for their distillation process. The end result is smooth and spicy whiskey with notes of chocolate.