How people in old Siam kept their drinks cool
Before ice became a daily staple in Thai households and street stalls, Siam had its own clever ways of beating the heat—especially when it came to enjoying a cool drink. But how exactly did people manage to chill their beverages in the sweltering climate of 19th-century Southeast Asia? The answer lies in a fascinating blend of ingenuity, science and a little help from international trade.
Let’s rewind to the year 1840 during the reign of King Rama III. It was a time when Siam was opening up to the West and European customs were starting to influence the local elite. Frederick Arthur Neale, a European visitor, documented one such moment that gives us insight into early drink-chilling techniques in the region.
At a royal banquet hosted by King Pinklao, Neale observed an inventive method of cooling champagne. Instead of relying on ice—which was nearly impossible to find in tropical Siam at the time—the court used a mixture of saltpetre (potassium nitrate), salt and water.
When these ingredients are combined, they create an endothermic reaction, which absorbs heat and significantly cools the surrounding liquid.
By placing the champagne bottles in this chilly bath, the drinks could be cooled down, even if they didn’t reach the frosty temperatures we enjoy today.
This method wasn’t unique to Siam. It was actually borrowed from India and other parts of Asia, where similar techniques had long been used in the absence of refrigeration.
What’s remarkable is how this chemistry-based approach showed an early understanding of thermal dynamics—long before the age of electric freezers and ice-making machines.
Things changed dramatically during the reign of King Rama IV, when ice finally made its debut in Siam. Imported from Singapore, massive blocks of ice were wrapped in sawdust for insulation and shipped to Bangkok.
By the time they arrived, only small, usable chunks remained—but it was revolutionary. For the first time, people in Siam could enjoy genuinely cold drinks and ice quickly became a luxury item among the upper class.
Ice's popularity only grew from there. By the early 20th century, the first ice factories had opened in Thailand, making it more accessible to the general public.
Today, it’s hard to imagine Thai life without ice—from iced coffees and sweet drinks sold on the street to shaved-ice desserts and traditional treats like ไอติมหลอด (tube ice cream).
In fact, that last one might be the sweetest legacy of all. Tube ice cream, still sold in colourful pushcarts across Thailand, is made using metal moulds chilled in a container filled with salt and ice—eerily similar to the salt-based method used in King Pinklao’s time.
It’s a perfect example of how old techniques can find new life in everyday culture.
So next time you enjoy a cold drink in Thailand, remember that keeping cool isn’t always so easy. From royal banquets to street-side snacks, the story of ice in Siam is a cool slice of history that’s still melting into the present.
