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Jin Xuan (Milk Oolong): The Creamy TRES #12 Cultivar

There is no tea more misunderstood, and more often faked, than Milk Oolong. In the West, it often smells like cheap vanilla car air freshener. But in Taiwan, the authentic article is subtle, buttery, and deeply comforting.

The true Milk Oolong is not flavored. It comes from a specific plant cultivar called Jin Xuan (TRES #12). Released in 1980 by the Taiwan Tea Research and Extension Station, this plant was bred to be the "People's Tea"—hardy, high-yielding, and naturally creamy.

In this deep dive, we explore the genetics of TRES #12, the chemistry of the lactones that give it that milky aroma, and how to spot the difference between the real deal and the chemical imposters.

A close-up of rolled Jin Xuan tea pearls and a cup of pale yellow liquor.

Cultivar Profile: Jin Xuan (TRES #12)

Origin: Taiwan (TRES), Released 1980
Parentage: Ying Zhi Hong Xin (Hard Red Stem) x TRES #8
Commercial Name: Golden Daylily (Jin Xuan)
Flavor: Milk, Butter, Sweet Corn, Cream
Key Molecule: Lactones (Coumarin, Jasmine Lactone)

Key Takeaways

1. History: The "Golden Daylily" Project

In the 1970s, Taiwan's tea industry was struggling. The traditional cultivars like Qing Xin were fragile, slow-growing, and only thrived on high, expensive mountains.
The TRES (Taiwan Tea Research and Extension Station), led by the legendary "Father of Taiwan Tea" Dr. Wu Zhenduo, spent 27 years developing a solution. They needed a plant that was:
1. High Yield: Grew fast and produced more leaves.
2. Hardy: Could resist pests and grow at lower, hotter altitudes.
3. Delicious: Had a unique flavor to distinguish it from competitors.

The winner was Strain #2027, officially released in 1980 as TRES #12. Dr. Wu named it "Jin Xuan" (Golden Daylily) in honor of his grandmother. It was an instant hit, saving the livelihood of thousands of lowland farmers.

2. The Chemistry: Why Does It Taste Like Milk?

The "Milky" flavor comes from a specific group of volatile organic compounds called Lactones.
While Linalool smells like flowers and Leaf Alcohol smells like grass, Lactones smell like fat, wax, and coconut.

Key Molecules in Jin Xuan:
1. Jasmine Lactone: Fruity, creamy, peach-like.
2. Coumarin: Sweet, vanilla-like, hay-like.
3. (Z)-3-Hexenyl Hexanoate: Green apple and pear.
When lightly oxidized and roasted, these compounds combine to create a sensory illusion of sweet cream or buttered corn. This aroma is naturally subtler than artificial flavoring, lingering in the back of the throat rather than exploding in the nose.

Expert Tip: Real vs. Fake

Natural Jin Xuan: The dry leaf smells grassy and floral. The milk note appears only after brewing and is subtle, often described as "Buttered Edamame." The flavor fades naturally over 3-4 infusions.
Flavored "Milk Oolong": The dry leaf smells aggressively like vanilla or condensed milk (often masking low-quality tea). The flavor is overwhelming in the first cup but disappears completely by the second brew because the surface oil has washed off.

3. Jin Xuan vs. Qing Xin: The Rivalry

Jin Xuan is often compared to Qing Xin (Green Heart), the king of High Mountain tea. While Qing Xin is aristocratic and floral, Jin Xuan is populist and creamy.

Feature Jin Xuan (TRES #12) Qing Xin (Green Heart)
Flavor Cream, Butter, Sweet Corn Orchid, Forest, Mineral
Texture Thick, Smooth, Oily Crisp, Clean, Refined
Altitude Low to Mid (400m - 1200m) High (1200m - 2600m)
Leaf Shape Oval, Wide, Obtuse Angle Narrow, Pointed, 45° Angle
Price Affordable / Everyday Premium / Expensive

4. Brewing Physics: Maximizing Creaminess

Jin Xuan is a hardy leaf that can withstand higher temperatures, but to maximize the "Milky" sensation (which is partly texture/pectin), you need to manage the extraction.

The Temperature: 95°C - 100°C.
Unlike Green Tea, tightly rolled Oolong needs heat to unfurl.
The "Rinse": Always do a quick 5-second rinse with boiling water. This warms the pot and starts the opening process. Smell the wet leaves immediately after the rinse—this "Hot Scent" (Re Xiang) is the best time to detect the natural buttery notes.
The Vessel: A porcelain Gaiwan is ideal for smelling the aroma. A high-fired clay pot can help round out the texture, emphasizing the creamy mouthfeel.

Taste the Real Thing

We have sourced Authentic, Unflavored Jin Xuan from the Alishan region. Experience the natural butter notes without the chemical aftertaste.

Shop Authentic Jin Xuan

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