From Coffee Beans to Oliang Blends: A Visual Guide to Traditional Thai Coffee
Discover the world of traditional Thai coffee blends, from dark-roasted coffee beans to the sweet, smoky oliang. Learn how ingredients like corn, soybeans, and sesame seeds create its unique flavor, and how to brew it at home with simple tools.
Contents
Traditional Thai coffee blends, known as oliang, are a unique departure from typical coffee. Unlike the bright, acidic notes of light-roasted Arabica, oliang is a dark, almost charred blend of coffee beans and roasted grains, brewed strong and served sweet over ice. This article explores how oliang is made, from bean to cup, and why its deep, smoky flavor is beloved in Thailand.
What Is Oliang? Understanding the Blend
Oliang (also spelled oleang) is a traditional Thai iced coffee made from a blend of dark-roasted coffee beans and various roasted grains and seeds. The name comes from the Teochew Chinese words "o" (black) and "liang" (cold). The blend typically includes coffee beans, corn, soybeans, sesame seeds, and sometimes rice or tamarind seeds. These ingredients are roasted until very dark, sometimes with butter or sugar, then ground and brewed using a cloth filter called a tungdtom. The result is a coffee with a distinctive smoky, earthy taste and a syrupy body, often served with sweetened condensed milk and evaporated milk over ice.
From Bean to Blend: The Roasting Process
The key to oliang's flavor is the roasting. Coffee beans, usually Robusta, are roasted until they are nearly black and oily, developing a bold, bitter base. Other ingredients are roasted separately to their own optimal darkness:
- Corn adds sweetness and a toasted, nutty flavor.
- Soybeans contribute creaminess and a mild, beany note.
- Sesame seeds provide a rich, nutty aroma and a slightly oily texture.
- Rice (when used) lightens the body and adds a subtle toastiness.
These roasted ingredients are then coarsely ground and mixed in varying proportions. The result is a blend that is less acidic than pure coffee, with a complex, smoky profile.
Key Ingredients and Their Roles
Each component in an oliang blend plays a specific role:
| Ingredient | Contribution | Visual and Aromatic Cues |
|---|---|---|
| Coffee beans (Robusta) | Strong, bitter base; caffeine | Dark, oily beans; intense roasted coffee smell |
| Corn | Natural sweetness, toasted flavor | Golden-brown kernels after roasting; aroma of popcorn |
| Soybeans | Creaminess, nutty undertone | Deep brown; smell of roasted nuts |
| Sesame seeds | Nutty aroma, slight oiliness | Tiny, dark seeds; strong nutty fragrance |
| Rice (optional) | Lighter body, subtle toast | Pale to brown grains; subtle roasted grain scent |
When combined, the blend has a coarse, rustic appearance with varying shades of dark brown and black. The aroma is intense: charred, nutty, and toasty, with a hint of sweetness from the corn.
How to Brew Oliang at Home
Brewing oliang traditionally requires a cloth filter, but you can approximate it with common tools. Here's a simple method:
- Measure the blend: Use about 4 tablespoons of oliang powder per 1 cup of water.
- Prepare your filter: Place the powder in a cloth filter (or a French press or drip cone with a paper filter).
- Heat water: Bring water to a near boil (around 200°F / 93°C).
- Pour and steep: Slowly pour water over the grounds. If using a cloth filter, let it drip through once, then pour the coffee through the grounds again (a process called "double-dripping") for a stronger, more syrupy brew.
- Sweeten and serve: Traditionally, add 1-2 tablespoons of sweetened condensed milk and a splash of evaporated milk. Stir well, pour over a glass full of ice, and enjoy.
If you can't find pre-mixed oliang powder, you can make your own blend. Start with a ratio of 50% dark-roasted coffee, 30% roasted corn, 15% roasted soybeans, and 5% roasted sesame seeds. Adjust to taste.
How Oliang Differs from Other Coffees
Oliang is often confused with es yen (Thai iced coffee with milk) or Vietnamese iced coffee. However, oliang is distinct because it is a blend of coffee and grains, not pure coffee. It is also less acidic and more savoury-sweet than Western iced coffees. In Thailand, oliang is often sold by street vendors in tall glasses, sometimes with a tungdtom filter perched on top, looking like a small metal or cloth basket.
Accessible Substitutes and Their Limitations
If you cannot find oliang powder, you can create a similar flavour using:
- Strong dark-roast coffee (like French roast) plus a small amount of roasted barley tea or roasted chicory. This mimics the smoky, grainy notes but will not have the same creamy sweetness from corn and soybeans.
- Postum or other grain-based coffee substitutes can be added to coffee to reduce acidity and add toastiness.
These substitutes will get you closer to oliang, but they lack the true complexity of the traditional blend, especially the nutty sesame and sweet corn notes.
Oliang is more than just coffee—it's a cultural experience in a glass. Its dark, rustic appearance, intense aroma, and bold flavour make it a fascinating introduction to Thai culinary traditions. Whether you enjoy it from a street stall in Bangkok or brew it at home, oliang offers a deliciously different coffee adventure.