Water is the easy default drink in Thailand – but drink it bottled, not from the public water system (i.e. taps/faucets). Free in many restaurants, and inexpensively purchased from convenience stores, street vendors, supermarkets, and water dispensers, you’ll probably be drinking lots of it in Thailand’s tropical climate.
Beer is a favourite with tourists and locals alike. Local varieties, such as Chang (which is Thai for ‘elephant’; Thai beers tend to be named after animals), tend to be light and refreshing, with plenty of flavour, although not necessarily to everyone’s taste. Imported beers are also common in tourist destinations but these do cost more than the local brew.
Thai wines can be pretty rough, although local manufacturers also try to add interest with ranges of fruit wines, which are generally good, and akin to English country wines. For quality wines, expect to be paying a premium for imported bottles. There are however, some expats who have now set up their own import businesses (there are at least two in Chiang Mai); their prices and ranges are very good.
Locally-produced liquors have attracted many myths (from their alleged aphrodisiac and healing powers, to rumours that they contain opium or amphetamines) but the myths are untrue, and in reality they are notable mainly for their fearsome alcohol content. Local liquors are far less expensive than their imported counterparts.
Coffee is grown locally, and it is well-worth seeking out fair trade local varieties grown by small farmers and hill tribes (such as Akha Ama in Chiang Mai).
Tea (as an English-style hot beverage) is not common, except in tourist-oriented venues, but flavoured iced teas are plentiful, varied, exotic, and in most cases, refreshing.
Thailand, as a tropical country, has an excellent range of fresh fruit available, – mostly locally-grown – and street vendors, bars, and restaurants all turn these into often excellent fruit drinks. Yogurt based milkshakes (often inaccurately described as lassis) are a satisfying, thick, and often very sweet beverage. However, the most common fruit beverage is a simple blend of fruit, water and ice, which can be extremely refreshing, and will set you back around 20 baht ($0.65/£0.40/€50) from a street vendor, and roughly 40 baht in a restaurant or café.