Why is Thai iced coffee so sweet?

Thai iced coffee has become an increasingly popular drink around the world in recent years. Known for its strong, sweet taste, Thai iced coffee is made from dark roasted coffee beans blended with various spices and sweetened with sugar and condensed milk or creamer. But why exactly is Thai iced coffee so sweet compared to other iced coffee drinks?

The History of Thai Iced Coffee

To understand the sweetness of Thai iced coffee, it helps to look at the history of how this drink developed in Thailand. The origins can be traced back to the 19th century when coffee was first introduced to Thailand during the reign of King Rama III. At that time, coffee was an expensive import and considered a luxurious drink that was unaffordable to most Thai people.

To make coffee more accessible, street vendors started blending coffee with spices such as cardamom, tamarind, and chicory root. These additives helped enhance the coffee’s flavor and aroma while using less actual coffee. The vendors also mixed the brewed coffee with sugar and condensed milk, which allowed the scarce coffee to be stretched further. The result was an affordable, sweeter, and uniquely Thai version of iced coffee.

This style of sweet, spiced iced coffee became popular in Thailand over the next century, evolving into the drink we know today. The abundance of sugar and dairy became hallmarks of authentic Thai iced coffee as it allowed people of all economic backgrounds to enjoy this once elite beverage.

Role of Condensed Milk and Sugar

Two ingredients that set Thai iced coffee apart are sweetened condensed milk and sugar. Sweetened condensed milk has been used in Thai tea and coffee recipes for over a century. This creamy, sweet milk product is made by removing about 60% of the water from regular milk and adding sugar before canning. The result is milk with a smooth, syrupy texture and rich sweet taste.

Sweetened condensed milk adds several dimensions to Thai iced coffee:

  • It provides a sweet, velvety texture to balance the drink’s strong coffee taste.
  • It enhances the aroma of the coffee and spices.
  • It allows the use of less actual coffee while still achieving a rich, indulgent flavor.
  • It makes the drink affordable for Thai street vendors to produce.

On top of the sweetened condensed milk, Thai iced coffee recipes also call for brewing the coffee with sugar or mixing in simple syrup. This extra sugar combines with the creamy milk to produce an intensely sweet, dessert-like coffee drink.

Unique Brewing Method

Another factor that influences the sweetness of Thai iced coffee is the unique way it is brewed. Unlike typical Western iced coffee that is cold brewed or brewed hot before being chilled, Thai iced coffee is prepared using a method sometimes referred to as “hot-brewing.”

The process involves:

  1. Brewing ground coffee beans and spices with hot water and sugar to produce a highly concentrated syrup called “Oliang.”
  2. Separately heating and frothing condensed milk.
  3. Combining the frothed milk and the Oliang syrup together.
  4. Pouring the mixture over ice to produce chilled Thai iced coffee.

This hot brewing method extracts more bitter compounds from the roasted coffee compared to cold brewing. The heat also allows the sugar, spices, and dairy to fully dissolve to make a sweet, potent coffee concentrate. The end result is an ultra-strong and sweet Thai iced coffee that would be difficult to achieve with cold brewing.

Spices and Flavorings

Although coffee is the star of Thai iced coffee, various spices, chicory root, and other flavorings are also common ingredients. Some classic spices added to enhance the coffee’s flavor profile include:

  • Cardamom – One of the most popular spices used, cardamom adds hints of spice and a pleasant aroma. It also enhances the coffee’s sweetness.
  • Tamarind – The sour tamarind fruit adds tartness to balance the drink’s sweetness and enhances the dark, roasted flavors.
  • Star anise – Adds aroma and a mild aniseed flavor that pairs well with the milk and sugar.
  • Vanilla – Small amounts of vanilla extract complement the vanilla notes in the creamy condensed milk.
  • Orange blossom water – Sometimes added for a subtle citrusy floral aroma.
  • Chicory root – Used as a coffee extender, chicory root adds an earthy, nutty element and enhances the body.

These spices and flavorings lend a signature aroma and taste to Thai iced coffee. Their additions, especially cardamom and tamarind, boost the drink’s sweetness and mask some of the coffee’s natural bitterness. This results in a sweeter coffee profile compared to drinks made from coffee alone.

Regional Variations

While sweetened condensed milk and sugar form the backbone of Thai iced coffee everywhere, there are some regional differences across Thailand worth noting:

Northern Thailand

Northern Thai iced coffee tends to use relatively more ground coffee beans compared to spices. The coffee flavor is robust, with cardamom and tamarind used sparingly to complement the coffee rather than overwhelm it. The sweetness comes mainly from the condensed milk rather than extra sugar.

Northeastern Thailand

In Isan or Northeastern Thailand, Jasmine flowers are often brewed alongside the coffee. Jasmine adds floral aromas and a subtly sweet taste. The iced coffee here has a delicate, clean flavor compared to other regions.

Southern Thailand

Strong, intense coffee flavor is the highlight of Southern Thai iced coffee. Spices like star anise, vanilla and cardamom are used generously. Both condensed milk and evaporated milk are common additions for extra creaminess. The sweetness is cranked up with plenty of white sugar.


As the cosmopolitan capital city, Bangkok serves a range of Thai iced coffee styles. Both condensed and evaporated milk are popular add-ins, and palm sugar is often used to sweeten the drink. Overall, Bangkok Thai iced coffee strikes a balance between strong coffee flavor and indulgent sweetness.

So while sweetened condensed milk is a constant, the additional spices, brewing methods, and sweeteners vary across regions resulting in different taste profiles. But in all areas of Thailand, serving intensely sweet, strong coffee over ice is the norm.

Cultural Preferences for Sweetness

Underlying the sweet taste of Thai iced coffee is a strong cultural preference for sweet foods in Thailand. Thai cuisine has been shaped by the tropical climate, the influence of nearby countries, and agriculture. As a result, many authentic Thai dishes feature prominent sweet and salty flavors.

This love for sweetness manifests in condiments like sugar, palm sugar, and sweet chili sauce paired with savory Thai dishes. Sweet coconut milk-based curries, sweet and spicy dipping sauces, and fried bananas are other examples of the Thai palate’s affinity for sweetness. Therefore, the sugary flavor profile of Thai iced coffee aligns with the Thai sensibility for dessert-like sweets.

Thai iced tea, another famous drink, is likewise prepared ultrasweet by brewing black tea with sugar and topping it with sweetened condensed milk. So while intense sweetness might overpower other cultures’ coffee preferences, it is perfectly normal for Thai iced coffee.

Meant to be Savored Slowly

One of the hallmarks of Thai food and drink is balance between different tastes – spicy, sour, salty, sweet, and bitter. Thai iced coffee achieves this balance with the bitter coffee and milk balancing out the sweetness. The idea is that the sweetness makes the bitter coffee more palatable when consumed slowly.

Thais do not gulp down iced coffee like a quick pick-me-up. Thai iced coffee is meant to be leisurely enjoyed, sip by sip, allowing the sweetness to gradually mellow out the harsher flavors. Similarly, sweet and spicy Thai dishes are meant to be eaten slowly so the palate can adjust to the heat. So while intensely sweet at first taste, Thai iced coffee develops a more balanced profile when slowly enjoyed.

Modern Innovations and Trends

While traditional Thai iced coffee is defined by its classic ingredients, modern cafes are putting new spins on this drink:

Cold Brewing

Some urban cafes now use cold brewed coffee instead of the hot brewing technique to create lighter, less bitter Thai iced coffee drinks.

Non-Dairy Milks

Plant-based milks like soy, coconut, and oat milk are replacing condensed milk for vegan adaptations.

Single Origin Beans

Specialty coffee shops are experimenting with single origin beans from coffee regions like Ethiopia or Guatemala rather than typical Thai robusta beans.

Premium Toppings

Upscale versions may be topped with Thai milk foam made from butter or coconut creamer rather than condensed milk for a richer texture.

Alcoholic Versions

For evening drinking, some urban bars serve Thai iced coffee spiked with rum or Thai spirits.

These creative twists keep Thai iced coffee feeling fresh while preserving the drink’s iconic sweetness. Even with lighter, vegan-friendly ingredients, Thai iced coffee still retains its distinctly sweet flavor profile.


Authentic Thai iced coffee isdefined by its addictive sweetness, owed to the combination of condensed milk, cane sugar, and natural spices. The origins of this sweet drink lie in making coffee accessible for all Thais. And the sweet flavor aligns with cultural preferences for dessert-like tastes. While international cafes sometimes tone down the sweetness, traditional Thai iced coffee fully embraces the strong, sugary flavors that make it so memorable. So next time you take a sip of silky, sweet Thai iced coffee, savor its rich history and cultural traditions hidden within each drop.

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