Sun Moon Lake (日月潭, Rì Yuè Tán) is Taiwan’s most famous natural lake, situated at 760 meters elevation in Nantou County. The tea-growing highlands surrounding the lake form the heartland of Taiwanese black tea production, producing Ruby 18 (Red Jade), TRES cultivar black teas, and assamica-based teas with a full-bodied, smooth character defined by the region’s subtropical microclimate.
Regional Profile
| Feature | Detail |
|---|---|
| Location | Nantou County, central Taiwan |
| Elevation | Lake surface: 762m; tea gardens: 760–1,200m |
| Annual rainfall | ~2,200mm |
| Soil | Red acidic loam; volcanic influence |
| Key cultivars | TRES No. 18 (Ruby 18), TRES No. 21, Assamica |
| Primary tea type | Black tea; some innovative processing |
| Key producers | Sun Moon Lake Tea Area; ~70 registered estates |
Climate and flavor: The lake itself creates a local micro-humidity, producing morning mist that buffets the surrounding tea gardens. This moisture, combined with the subtropical highland temperature range (averaging 18–28°C), slower growth cycles, and rich soil, concentrates aromatic compounds in the leaf. The result is black teas that are:
- Smooth and round with low astringency
- Full-bodied without being sharp
- Distinctively aromatic — especially the signature cinnamon-mint of Ruby 18
History
Japanese colonial era (1895–1945): The Japanese colonial government identified the Sun Moon Lake area as ideal for commercial black tea cultivation after studying British Assam cultivation models. Large-leaf Camellia sinensis var. assamica seeds and cuttings were imported from Burma and India, establishing the region’s first commercial black tea gardens by the 1920s–1930s. Production was aimed primarily at export markets.
Post-WWII Taiwan Tea Research and Extension Station: After WWII, the Taiwanese government maintained the TRES (台灣茶業改良場) in the Sun Moon Lake area. Systematic cross-breeding programs ran for decades, eventually producing Cultivar No. 18 (Ruby 18, released 1999) and No. 21 (released ~2008), among others. These cultivars transformed the region from a commodity assamica producer into a specialty tea destination.
Specialty era (2000s–today): The release of Ruby 18 and the growing international specialty tea market drove significant quality upgrading. Small-batch artisan producers, direct-trade partnerships, and tea tourism all developed around the region.
Key Teas from Sun Moon Lake
Ruby 18 / Red Jade (TRES No. 18): The flagship cultivar; unique cinnamon and mint notes produced naturally by plant chemistry. Taiwan’s most internationally recognized black tea.
TRES No. 21 / Hongyucha (紅玉茶): A newer cross with a lighter, more citrus-floral profile. Less distinctive than Ruby 18 but highly drinkable; aimed at a broader market segment.
Assam-origin varieties: Older plantings from the Japanese-era assamica introduction; produces full-body, malty black teas that resemble Assam in character.
Common Misconceptions
“Sun Moon Lake is primarily known for oolong.” Taiwan is broadly famous for oolong teas, but Sun Moon Lake is specifically the center of Taiwanese black tea production. The high-mountain oolong regions (Nantou, Alishan, Lishan) are different growing zones.
Related Terms
See Also
- Ruby 18 Tea — the signature cultivar produced in this region
- Nantou County — the administrative region containing Sun Moon Lake
Research
- Chen, Y.L., et al. (2010). “Cultivar comparison in Taiwanese black teas from Sun Moon Lake.” Taiwan Agricultural Research, 59(3), 203–215. Regional overview confirming that the specific microclimate around Sun Moon Lake — low-diffuse light, sustained humidity, volcanic soil — contributes measurably to the aromatic compound concentration in both Ruby 18 and TRES No. 21 teas.
- Tea Research and Extension Station of Taiwan (2015). Annual Report: Sun Moon Lake Tea Industry Survey. TRES internal publication. Documents the transition of the Sun Moon Lake tea industry from commodity production to specialty artisan cultivation, driven primarily by the commercial success of TRES-developed cultivars in international markets.