Let’s examine one of the most misunderstood—and arguably most exciting—categories in the tea world: oolong tea. If you’ve ever wondered what oolong is, why it can taste so different from cup to cup, or why it’s under appreciated in the U.S., this post is for you.

What Is Oolong Tea?

The simplest definition: oolong is a semi-oxidized tea. That means it sits in the middle of the oxidation spectrum—between green tea (unoxidized) and black tea (fully oxidized).

This means that oolong is the range of tea that is oxidized from around 11% all the way up to around 70%. That’s a huge range! And within that spectrum lies an incredible diversity of flavors, aromas, and styles.

The Core Variables That Shape Oolong

So why do oolongs vary so much? Here are five major factors that shape the flavor that ends up in your cup:

1. Oxidation Level

From lightly oxidized floral oolongs to red honey chocolaty ones oxidation is the foundation that determines the direction of flavor.

2. Cultivar

Did you know there are 40–50 recognized oolong cultivars? If you include regional strains and local variants, that number balloons to nearly 100. Different cultivars yield vastly different flavors—from creamy and buttery to honeyed or woody.

3. Terroir

Yes, tea—like wine—expresses terroir. This refers to the complete environment where the tea is grown: soil, elevation, climate, sun exposure, humidity, etc. A tea grown at high elevation in Taiwan will taste radically different than one grown closer to sea level in Fujian.

4. Processing Style

This is where artistry comes in. The tea master decides whether the tea is:

• Charcoal-roasted or oven-roasted
• Tightly rolled or twisted leaf
• Pan-fried, baked, or left to sun wither

Each choice shapes the final character of the tea.

5. Seasonality

Spring harvest? Summer? Autumn? Winter? Even within the same tea garden and cultivar, a spring-picked tea will express itself differently than a late-summer one.

Why Is Oolong Tea Overlooked in the U.S.?

Back when I first got into the tea business in the early 2000s, I noticed something odd: many coffee shops stocked an oolong they called "Formosa Oolong." It was often dark, flat, and unimpressive. Most of the time, it wasn’t even from Formosa (the old name for Taiwan)!

It turned out this "Formosa Oolong" was usually a low-grade roasted tea from China, mass-marketed under a name that sounded exotic. The result? Many people's first taste of oolong was one-dimensional and uninspiring. Unfortunately, that impression stuck.

Meanwhile, truly exceptional oolongs—like Taiwan’s Eastern Beauty (bug-bitten and honey-sweet) or a high-mountain Four Seasons Spring (light, floral, vibrant)—weren’t making it into mainstream shops. The category was reduced to “somewhere between green and black,” when in fact, oolong is a galaxy of its own.

Let’s Taste the Difference

Earlier today, I brewed three oolongs. They look and taste completely different:

1. Green Oolong – Floral, light, refreshing. Cultivar: Four Seasons Spring. Great hot or iced.
2. Bug-Bitten Summer Oolong (True Formosa) – Often labeled as Eastern Beauty or Formosa. It has a honeyed character and a complex, crisp mouthfeel.
3. Wuyi Rock Oolong (Yancha) – Roasty, intense, with cinnamon and mineral notes. Grown in the rocky soils of Fujian, China.

If you tasted these three side by side, you’d be shocked they’re all part of the same category. But that’s the magic of oolong—its range is unmatched.

So… What Makes an Oolong an Oolong?

In the most technical sense: it’s semi-oxidized tea.

But in practice, it’s the sum of dozens of variables—oxidation, cultivar, terroir, processing, season—all masterfully aligned to create something nuanced, expressive, and uniquely delicious. A good oolong truly is a work of art.

Why We Should Care

Oolong deserves more attention. It's not just “between green and black.” It's an art form, a bridge between tradition and innovation, and a celebration of diversity in tea.

If you haven’t explored oolong beyond the Formosa of the past, now’s the time. My hunch is that if you think you don’t like oolong tea, it is probably because you have not yet had the right oolong for you. Don’t give up on this category. Keep trying.