What’s the difference in flavor between loose leaf oolong tea with different roasting levels? And how can you tell how much a tea has been roasted? In this blog, we’ll break it down for you from different angles.
1. The Role of Roasting in Oolong Tea Flavor
Roasting plays a vital role in the flavor development of Oolong tea—it’s far more than just “adding heat.”
When done right, roasting doesn't flatten the tea flavor; it enhances it. A well-roasted Oolong gains more depth and complexity. The liquor becomes richer and more full-bodied, while the aroma shifts from bright, piercing florals to a more rounded profile of ripe fruitiness and gentle sweetness.
Now, it’s true that higher roast levels can introduce a charcoal aroma. But a skilled tea maker can create a beautiful, subtle harmony between the roast and the tea’s natural fruity and sweet aromas, rather than letting the fire overpower everything.
Achieving that balance isn’t easy. It can take decades—sometimes even generations—to master.
2. Roast Level Categories
The way roast levels are classified in China, especially in Fujian, is surprisingly detailed. It’s not just “light” or “dark” roast.
Traditionally, there are five main roast levels used to describe Oolong teas:
- Very Light Roasted (微火) – also called Zou Shui or Qian Huo, the aroma is clean and pure, and you can still detect the fresh, raw scent of the maocha.
- Light Roasted (轻火) – The roasting starts to change the aroma, retaining more of the tea’s natural green and floral character
- Medium Roasted (熟火) – sometimes called Shu Huo or Ban Sheng Shu, starts to get subtle charcoal fragrance, with no grassy or raw flavors. The aroma leans more toward fruity, and the taste becomes rounder and more full-bodied.
- Full Roasted (足火) – more developed roasting, bringing out deeper sweetness aroma and a rounder flavor
- Heavy Roasted (重火) – also called Lao Huo or Gao Huo- tastes strong charcoal notes or burnt notes, and much of the tea’s original character is lost at this point.
Each level affects not only the appearance of the dry leaves but also the aroma, liquor color, and taste in the cup.
One thing especially interesting: when brewing medium or full roast Oolong tea, lots of little bubbles are on the surface of the wet leaves. In China, tea lovers often refer to these bubbles as “toad skin” (蛤蟆背)—and it’s actually a classic sign of traditional charcoal roasting.
3. What Determines the Roast Level of Oolong Tea
From time to time, we’ve heard things like:
“High mountain teas are all about fragrance and should only be lightly roasted.”
“Lowland teas are lower quality and need heavy roasting to cover it up.”
Or even, “Heavily roasted teas are just cheap teas.”
It’s a bit different from what you might expect.
Some veteran tea makers from Chaozhou and Wuyishan believe that whether an Oolong is suitable for roasting—and to what degree—should depend entirely on the maturity of the fresh leaves and the level of oxidation during processing. In China, there’s a saying: “kan cha pei huo” (看茶焙茶), which roughly means “roast the tea based on the leaf.” We can’t judge tea quality just by how heavily it’s roasted.
- Tender, young leaves often undergo light oxidation. At this stage, polyphenols—responsible for bitterness and astringency—haven’t fully converted. If the tea master roasts these leaves too heavily, not only do the floral high aroma (which are often low-boiling aromatic compounds) get burned off, but they might bring out more bitterness.
- More mature leaves with a higher oxidation level need a stronger roast to fully bring out their potential. The heat helps develop and stabilize the richer, more complex aroma compounds.
4. How Roast Level Affects Oolong Tea Caffeine?
During high-temperature roasting, some of the caffeine can actually evaporate from the tea leaves and later re-condense either on the leaf surface or inside the roasting equipment.
This might help explain why some heavily roasted Oolongs—especially those made from mature leaves with proper oxidation tend to have lower caffeine content.
5. How to Identify the Roast Level of Oolong Tea?
You can get a rough idea of the roast level of an Oolong by looking at the dry leaves and the liquor color.
- Lightly roasted teas usually have a dark green or slightly greenish hue, and the liquor tends to be a bright golden yellow.
- Heavier roasts often produce dark brown leaves, and the liquor shifts toward a deep orange or amber tone.
6. Why Does Charcoal-Roasted Oolong Tea Need to Rest?
After roasting, the tea doesn’t reach its best flavor right away—it actually needs a bit of resting time.
This resting period helps the strong charcoal notes mellow out, allowing the tea’s true aroma and flavor to emerge more clearly. The heavier the roast, the longer this "cooling off" phase tends to take:
- Light roast teas usually need around 1–2 months
- Medium to full roast teas may need 3–5 months or more
- Some heavily roasted Oolong teas are more suitable for long-term storage. After 1–2 years of proper storage, they might become even smoother, deeper, and more enjoyable.
7. Our Recommended Products：
1.This product includes three different roasting levels of Wuyi Rougui—light roast, medium roast, and full roast. Each tea has its own unique flavor profile, making it perfect for exploring and discovering your favorite level of roasted oolong.
Wuyi Oolong Comparison Set: 3 Roast Levels 60g
2. This product features both charcoal-roasted and electric-roasted versions of Phoenix Dancong and Wuyi Rougui. By comparing these two types of oolong tea, you can experience the distinct charm of charcoal and electric roasting.
Oolong Roast Comparison Set--Charcoal vs Electric 80g
