Taiwan Ruby Black tea: the story of Hong Yu No. 18

Most black teas tell a familiar story: a robust, malty cup — good for mornings, good with milk, dependable. Taiwan Ruby Black tells a completely different story. It smells like ripe pineapple. It finishes with a cooling, almost minty freshness. It’s bold but never harsh. And every extraordinary note in the cup comes entirely from the leaf itself — no flavoring, no added fruit, no artificial aromatics of any kind.

This is the story of Hong Yu (紅玉) — Taiwan Cultivar No. 18 — one of the most remarkable tea developments in modern history, and the reason our Pineapple Ruby Black Tea tastes the way it does.

What is Taiwan Cultivar No. 18?

Taiwan Cultivar No. 18 — officially registered as “Tai Cha No. 18” — is a tea plant that exists nowhere else in the world. It was developed by Taiwan’s Tea Research and Extension Station through decades of careful breeding, crossing a wild-growing Taiwanese mountain tea (a native Camellia sinensis var. assamica found in Taiwan’s forests) with a large-leaf Assamica strain originally from Burma.

The goal was to create a cultivar suited to full oxidation that would produce a high-quality black tea with exceptional flavor clarity. What the researchers got exceeded expectations: a tea plant that, when fully oxidized, naturally produces one of the most distinctive flavor profiles in the entire world of tea.

The cultivar was officially named Hong Yu — meaning Ruby — for the deep red color of its brewed liquor. The color, like the flavor, comes entirely from the leaf.

Why does it taste like pineapple?

This is the question everyone asks — and the answer is genuinely fascinating. The tropical pineapple aroma in Ruby Black tea is not added. It is not a flavoring or an essence or a spray. It is a direct product of the cultivar’s own chemistry.

Taiwan No. 18 leaves contain unusually high concentrations of specific aromatic compounds — particularly linalool and geraniol, two terpene alcohols also found naturally in tropical fruits. During the slow, controlled oxidation process that transforms a freshly picked leaf into black tea, these compounds are released and amplified. What begins as a green, grassy leaf emerges from processing smelling unmistakably of ripe pineapple, warm honey, and sun-dried grass.

The cooling wintergreen finish — Ruby Black’s other signature characteristic — comes from methyl salicylate, another compound that occurs naturally in the No. 18 cultivar at higher concentrations than in virtually any other tea plant. It’s the same compound that gives wintergreen its distinctive cooling quality, and in Ruby Black it appears as a clean, refreshing aftertaste that makes the next sip irresistible.

No other tea cultivar in the world does this naturally. Taiwan No. 18 is genuinely one of a kind.

Sun Moon Lake: where Ruby Black is born

Taiwan No. 18 is grown predominantly around Sun Moon Lake — Ri Yue Tan (日月潭) — in Nantou County in central Taiwan. Sun Moon Lake is Taiwan’s largest natural lake, sitting at around 760 meters above sea level, surrounded by forested mountains and frequent mist.

The region’s climate is ideal for the Assamica-derived No. 18: warm and humid in summer, with cooler mountain nights and volcanic soil rich in minerals. Tea farms here are terraced into the hillsides, many of them tended by families who have been growing tea in this region for three or four generations.

Our Ruby Black is crafted by a third-generation tea maker whose family has worked with the No. 18 cultivar for decades. The leaves are hand-picked during the winter 2024 harvest, slowly withered to reduce moisture content, then carefully oxidized in small batches before a gentle low-heat finishing process that locks in the tropical aroma without adding heaviness. Every step is unhurried. Every batch is small. The flavor reflects both.

What does Taiwan Ruby Black tea taste like?

If you’ve only ever drunk Assam, Darjeeling, or Ceylon, Ruby Black will be a genuine surprise. Here’s what to expect:

1. Aroma (dry leaf): Intensely fruity and tropical — ripe pineapple skin, warm honey, and a hint of sun-dried grass. Even the dry leaf is remarkably fragrant.
2. Aroma (brewed): The tropical notes open and deepen. A gentle warmth underneath — caramel and dried fruit — with the pineapple still leading.
3. Flavor: Smooth caramelized fruit with a warm, gently spiced depth. Bold enough to satisfy, smooth enough to drink without milk or sugar.
4. Body: Full and rounded, with a satisfying weight in the cup that feels nourishing rather than heavy.
5. Finish: The cooling wintergreen — clean, refreshing, and lingering. It’s the detail that most surprises first-time Ruby Black drinkers and keeps them coming back.
6. Liquor: Deep ruby-amber, rich and luminous — the color the cultivar was named for.

How to brew Taiwan Ruby Black tea

Ruby Black is one of the most versatile teas in the DAE collection — excellent brewed simply in a mug, or explored across multiple gongfu infusions.

• Water temperature: 200–212°F (93–100°C) — near or fully boiling

• Western style: 1 tablespoon (3.5g) per 8 oz, steep 2–3 minutes. With or without milk — a small splash of whole milk brings out the caramel notes beautifully.

• Gongfu style: 3.5–5g per 180–250ml, first steep 1.5–2 minutes, extend gently with each subsequent pour

• Re-steeps: 3–5 infusions, each growing deeper and more caramel-like

• Cold brew: 5g per 600ml overnight in the refrigerator — the tropical fruit becomes vivid and extraordinarily clean

How Ruby Black compares to other black teas

Ruby Black is in a category of its own, but here’s how it sits relative to other well-known black teas:

1. vs Assam: Assam is bold, malty, and robust — built for milk and mornings. Ruby Black is smoother, sweeter, and far more aromatic, with tropical notes Assam never has.
2. vs Darjeeling: Darjeeling has floral, muscatel notes and a lighter body. Ruby Black has more body and sweetness, with a completely different tropical fruit character.
3. vs Ceylon: Ceylon is clean and citrusy with moderate body. Ruby Black is richer, more complex, and distinctly fruit-forward in a way Ceylon isn’t.
4. vs flavored black teas: Flavored teas add fruit oils or artificial aromatics to a base tea. Ruby Black’s tropical flavor is the tea itself — no base, no addition, just a cultivar that nature made this way.