Rìyuètán hóngchá

Riyuetan Hong Cha is the pride of Taiwanese red tea (black tea) cultivation, born in one of the most picturesque corners of the island — on the shores of Sun Moon Lake. This tea is the fruit of half a century of breeding, uniting the bloodlines of Indian Assam and wild Taiwanese mountain tea. Its calling card is the cultivar Tai Cha No. 18 “Hong Yu” (紅玉, “Red Jade”) — the only variety in the world with natural cinnamon and mint aromas, having no analogues in any tea-producing country.

1. Classification and Origin:

• Type: Red tea (black tea) (紅茶, hóngchá), fully oxidized (100% oxidation). According to European classification — black tea.
• Category: Premium Taiwanese red tea (black tea). Flagship of Taiwanese red tea cultivation. Yúchí District (魚池) is officially recognized as the “Birthplace of Taiwan’s Red Tea.”
• Origin: Táiwān (臺灣, Táiwān), Nántóu County (南投縣, Nántóu Xiàn), Yúchí Township (魚池鄉, Yúchí Xiāng) — the district surrounding Rìyuètán Lake (日月潭, Rìyuètán — “Sun Moon Lake”). This is Taiwan’s largest natural lake, located at 748 m above sea level in the central mountainous part of the island.
• Geographic coordinates: approximately 23°51′ N, 120°54′ E
• Alternative names: Taiwan Hóng Chá (臺灣紅茶); by specific cultivars: Hóng Yǔ (紅玉, “Red Jade” — Tai Cha No. 18), Hóng Yùn (紅韻, “Red Rhyme” — Tai Cha No. 21), Tai Cha No. 8 (台茶8號).

2. History and Cultural Significance:

• History: The history of red tea on Taiwan begins during the Japanese colonial period (1895–1945). In 1925, Japanese agronomists brought Assam tea plant seedlings (Camellia sinensis var. assamica) from India and planted them in several regions of Taiwan — in Pingzhen (平鎮) and Yúchí (魚池). The Yuchi district, thanks to its climate similarity to Assam, yielded the best results, and the Taiwan Governor-General (臺灣總督府) established the Yúchí Red Tea Experimental Branch (魚池紅茶試驗支所) here, the predecessor of the current Tea Research and Extension Station (茶業改良場魚池分場, TRES Yuchi Branch). Simultaneously, researchers discovered wild Taiwanese mountain tea (Camellia formosensis) — an endemic species of the island.

  In the 1930s, Taiwanese red tea experienced a golden age: export volumes reached 5.8 million jin (1937), with tea going to Japan and Russia. During World War II, most researchers were mobilized; only director Arai Kokichiro (新井耕吉郎) remained at the station, single-handedly maintaining the collection. In 1946, after Taiwan’s transfer to the Republic of China, breeders began a large-scale project: crossing Burmese large-leaf Assam tea B-729 (maternal line) with wild Taiwanese mountain tea B-607 (paternal line). 48 years were spent on selection, testing, and stabilization — and in 1999 the Executive Yuan officially named the new cultivar Tai Cha No. 18 (台茶18號), giving it the poetic name “Hong Yu” (紅玉, “Red Jade”) — for the intensely ruby-red color of the liquor.

  Irony of fate: in the same 1999, the devastating Jiji earthquake (921大地震, September 21, 1999, magnitude 7.6) devastated Yuchi — the epicenter was nearby. The catastrophe, however, became a turning point: the reconstruction program included targeted development of the tea industry, and Hong Yu became a symbol of Taiwan’s “red renaissance.” In 2008, another cultivar was developed at the same station — Tai Cha No. 21 “Hong Yun” (紅韻, “Red Rhyme”).

• Name:

  • “Riyuetan” (日月潭) — “Sun Moon Lake.” The name relates to the lake’s shape: the eastern part resembles the sun (日), the western part — a crescent moon (月).
  • “Hong Cha” (紅茶) — “red tea.”
  • “Hong Yu” (紅玉) — “Red Jade,” the poetic name of Tai Cha No. 18, referring to the ruby-red color of the liquor.

• Cultural significance: Riyuetan Hong Cha is a symbolic tea: a symbol of the region’s revival after the 1999 earthquake and a symbol of Taiwanese distinctiveness in the world of red tea. Tai Cha No. 18 “Hong Yu” is a unique Taiwanese endemic with no analogues anywhere in the world; its cinnamon and mint aroma cannot be reproduced with other raw materials. Sun Moon Lake is central Taiwan’s main tourist attraction, and the tea has become an integral part of the local brand.

3. Botanical Description and Raw Material:

• Variety / Cultivar: Main cultivars used for Riyuetan Hong Cha:
  • Tai Cha No. 18 “Hong Yu” (台茶18號 紅玉): Flagship. Hybrid of Burmese large-leaf Assam tea B-729 (C. sinensis var. assamica) × wild Taiwanese mountain tea B-607 (Camellia formosensis). Developed at TRES Yuchi Station over 48 years of breeding (1946–1999). Large leaves, abundant tips. Unique aromatics — natural notes of cinnamon (肉桂香, ròuguì xiāng) and mint/menthol (薄荷香, bòhé xiāng). Contains specific terpene compounds not found in other cultivars. Grows only on Taiwan — a world endemic.
  • Tai Cha No. 21 “Hong Yun” (台茶21號 紅韻): Newer cultivar (2008). Distinguished by muscatel-honey aroma with citrus overtones. Less common than No. 18.
  • Tai Cha No. 8 (台茶8號): Early Assam hybrid (1930s). Classic profile — malty-caramel, without cinnamon-mint notes. Used less frequently.
  • Assam varieties (大葉種): Pure Assam tea lines brought in the 1920s. Produce dense, rich red tea in the “Indian” style.
  • Taiwanese wild mountain tea (臺灣山茶, Camellia formosensis): Island endemic. Used rarely, but imparts a unique “forest” character.
• Harvest: Spring–autumn (March–November). Best season — summer (June–August): hot and humid climate promotes active growth of large-leaf raw material and accumulation of aromatic substances. Summer harvest of Tai Cha No. 18 is considered the “gold standard.”
• Picking standard: One bud with two-three leaves (一芽二三葉). Hand-picking is mandatory for premium batches (手採, shǒu cǎi).
• Raw material requirements: Large, healthy, undamaged shoots. Rapid delivery to the workshop.

4. Terroir and Cultivation Features:

• Sun Moon Lake: Taiwan’s largest natural lake, located at 748 m elevation in the mountains of the central part of the island. Surrounded by mountains covered with subtropical forests. The district’s climate — subtropical montane, with high humidity and abundant mists — proved remarkably similar to Assam conditions, which determined the choice of Japanese agronomists in 1925.
• Yuchi Township: “Fish Pond” (魚池) — the main tea-producing district. Tea gardens are located on hilly slopes around the lake, often among bamboo groves and forests.
• Growing elevation: 600–1,000 m above sea level. Main zone — 700–800 m.
• Climate: Subtropical montane monsoon. Average annual temperature — 20–22°C. Precipitation — ~2,000 mm/year. High humidity — 80–85%. Frequent mists, especially morning and evening. Warm summer, mild winter. Minimal diurnal temperature amplitude moderated by lake influence.
• Soils: Fertile red and lateritic soils, well-drained, rich in organics and minerals. Slightly acidic (pH ~4.5–5.5). Ideally suited for large-leaf Assam cultivars.

5. Production Technology:

The production technology of Riyuetan Hong Cha follows the classic scheme of fully oxidized red tea, but with a Taiwanese emphasis on “purity” and “clarity” of taste. Taiwanese masters strive for perfect oxidation balance: sufficient for full aroma development, but without “burning” and coarseness.

• Picking (採摘 — cǎizhāi): Hand-picking (手採) for premium batches; mechanized — for mass production.
• Withering (萎凋 — wěidiāo): Solar or indoor. Duration — 12–24 hours. Large-leaf Assam raw material requires longer withering than small-leaf Chinese varieties. Moisture loss — 60–70%.
• Rolling (揉捻 — róuniǎn): Machine (roller), but with careful pressure control. Large Assam leaves are fleshy and juicy; it’s important to achieve uniform juice extraction without crude structural destruction.
• Oxidation (發酵 — fājiào): At controlled temperature (~25–30°C) and humidity (~90–95%). Duration — 3–6 hours. For Tai Cha No. 18 — the master focuses on the appearance of characteristic cinnamon-mint aroma as a marker of optimal oxidation.
• Drying (烘乾 — hōnggān): Hot air in drying chambers. Temperature — 100–110°C. Aroma fixation and moisture removal to 3–5%. Without charcoal roasting (unlike Fujian traditions) — Taiwanese style is “cleaner” and “clearer.”
• Sorting (分級 — fēnjí): Separation into fractions by size and quality.

6. Organoleptic Characteristics:

Characteristics described for the main cultivar — Tai Cha No. 18 “Hong Yu” (most common and famous):

• Dry leaf appearance: Medium-length strips, tightly twisted, with golden-reddish tips. Color — dark brown to black, with oily luster. Leaves larger than small-leaf Chinese red teas — heritage of Assam lineage.
• Dry leaf aroma: Hong Yu’s calling card — natural aroma of cinnamon (肉桂香) and mint/menthol (薄荷香), having no analogues among other red teas of the world. Overtones — caramel, honey, tropical fruits (pineapple, mango), light woody note. Aroma is rich, persistent, instantly recognizable.
• Liquor aroma: Multi-layered. First layer — cinnamon and mint (fresh, mentholated coolness). Second — caramel, burnt sugar, honey. Third — light fruity notes (pineapple, lychee). With cooling — intensification of minty shade.
• Taste: Full, rich, with pronounced “body” (heritage of Assam blood). Dominants — cinnamon, mint, caramel, honey. Astringency — moderate, “silky,” without coarseness. Sweetness natural, not “sugary.” Aftertaste — long, with minty-cinnamon coolness and caramel sweetness. Returning sweetness (huí gān) (回甘) — pronounced.
• Liquor color: Deep ruby-red (“scarlet jade”), bright, clear. It was precisely for this color that the tea received the name “Red Jade.”
• Spent leaves (wet leaves): Large, whole, fleshy leaves of copper-red color, elastic. Assam heritage — leaves noticeably larger than Chinese red teas.

7. Chemical Composition:

The chemical profile of Tai Cha No. 18 reflects its hybrid nature — the large-leaf Assam component provides high polyphenol content, while the Taiwanese wild tea contributes unique terpene compounds.

• Polyphenols (茶多酚): High content (higher than small-leaf Chinese varieties, due to Assam lineage). Theaflavins and thearubigins form the deep ruby color and “velvetiness.”
• Amino acids (氨基酸): L-theanine and other amino acids. Content — moderate.
• Alkaloids: Caffeine — content lower than pure Assam, due to contribution of Taiwanese wild component.
• Aromatic compounds: Unique profile — high content of trans-cinnamaldehyde (cinnamon), menthol and menthone (mint), linalool, geraniol. It is precisely the ratio of these components that creates the inimitable “cinnamon-mint” character, not found in any other tea cultivar.
• Vitamins: C (partially), B₁, B₂, E.
• Minerals: Potassium, calcium, magnesium, iron, manganese, zinc.

8. Health Properties:

• Gentle stimulation: Caffeine combined with L-theanine provides smooth, sustained energy.
• Antioxidant action: High polyphenol content (Assam lineage) provides powerful antioxidant potential.
• Warming effect: Fully oxidized red tea is “warm” according to TCM. Cinnamon-mint profile enhances sensations of warmth and freshness simultaneously.
• Digestive support: Gently stimulates gastric juice secretion; cinnamon is traditionally considered beneficial for digestion.
• Cardiovascular support: Polyphenols and theaflavins improve vascular elasticity.
• Refreshing effect: Mentholated notes create a sensation of light coolness — the tea is excellent in hot weather as cold brew (冷泡, lěng pào).
• Anti-stress effect: L-theanine promotes a state of calm concentration.

9. Brewing:

• Water temperature: 90–100°C. Large-leaf Assam cultivar opens well with boiling water. For delicate batches — 90–95°C.
• Tea amount: 4–5 g per 100–120 ml (gongfu); 3 g per 200–250 ml (European method).
• Teaware: Porcelain gàiwǎn (蓋碗) 100–120 ml — optimal: neutral material reveals cinnamon-mint aroma without distortion. Glass teapot — allows admiring the ruby color of “Red Jade.” Yixing teapot — acceptable, but may muffle mentholated freshness.
• Process:
  1. Warm teaware: Rinse gaiwan, fairness cup and cups with boiling water.
  2. Add tea: 4–5 g in warmed gaiwan.
  3. Rinse (潤茶): Quick 2–3 second pour — optional.
  4. First infusion: 10–15 seconds.
  5. Pour: Completely drain liquor into fairness cup.
  6. Subsequent brewings: 5–8 infusions. Increase time by 5–10 seconds. First infusions — bright cinnamon and mint; middle — caramel and honey; final — soft woody sweetness.
• Cold brew (冷泡茶, lěng pào chá): Riyuetan Hong Cha is magnificent as cold brew: 5 g per 500 ml cold water, in refrigerator 6–8 hours. Cinnamon-mint coolness unfolds especially brightly when cold.

10. Storage:

• Container: Airtight, opaque — tin can, foil bag, ceramic vessel.
• Conditions: Dry, cool, dark place, away from foreign odors. 15–25°C, humidity up to 60%.
• Duration: 12–24 months. According to Taiwanese experts, Hong Yu “matures”: storage for 1 year after purchase can improve the profile, making it more “rounded” and “sweet.” Quality batches store up to 3 years.
• Refrigerator not necessary — red tea stores perfectly at room conditions.

11. Price and Counterfeits:

Riyuetan Hong Cha is a tea of medium and upper price segments. Tai Cha No. 18 “Hong Yu” — from 600 to 2,000 NTD (新臺幣) per 75 g (~150–500 yuan per 150 g); competition batches and hand-picked — significantly more expensive. Tai Cha No. 8 and Assam — cheaper.

How to avoid counterfeits:

• Check origin: Authentic Rìyuètán Hóng Chá is from Yúchí Township (魚池鄉), Nantou County. Look for “魚池鄉” indication on packaging.
• Look for cinnamon-mint aroma: For Tai Cha No. 18 — natural notes of cinnamon and menthol are the signature marker. If aroma is “ordinary” — sweet-malty without cinnamon — this is likely Tai Cha No. 8 or Assam tea, not Hong Yu.
• Evaluate liquor color: Deep ruby, bright, clear. Dull or cloudy — sign of low quality.
• Beware of abnormally low prices: “Hong Yu” for 100 NTD/75 g — suspicious.
• Pay attention to certificates: Taiwanese farmers often provide SGS certificates and competition award marks.

12. Interesting Facts:

• 48 years to birth: Tai Cha No. 18 “Hong Yu” is the result of one of the longest breeding projects in world tea history. Crossing began in 1946, and the new cultivar received its name only in 1999. Nearly half a century of selection, testing, and patience.
• Tea from earthquake: The “921” earthquake (September 21, 1999, M 7.6) that devastated Yuchi paradoxically became a catalyst for Taiwan’s “red renaissance”: the regional reconstruction program focused on tea industry development, and Hong Yu became its main symbol.
• The world’s only “cinnamon-mint” tea: Natural cinnamon and menthol aroma is a genetic feature of the “Assam × Taiwanese wild tea” hybrid. No other cultivar in the world possesses such an aromatic profile — this is not flavoring, but a natural property of the leaf.
• Arai Kokichiro — the man who saved the collection: During World War II, Japanese station director Arai Kokichiro (新井耕吉郎) single-handedly maintained the tea plant collection in Yuchi. Without his efforts, the program from which Hong Yu was born would have been impossible.
• Cold brew — Taiwanese tradition: Unlike mainland Chinese “hot gongfu” tradition, Taiwanese actively practice cold brew (冷泡茶) — and Hong Yu is considered one of the best teas for this format.

13. Varieties of Riyuetan Hong Cha:

• Tai Cha No. 18 “Hong Yu” (台茶18號 紅玉): Flagship. Assam × Taiwanese wild tea. Cinnamon + mint. Most famous and expensive. Taiwan’s world endemic.
• Tai Cha No. 21 “Hong Yun” (台茶21號 紅韻): Newer (2008). Muscatel-honey aroma with citrus overtones. Less “bright,” more “calm” in profile than No. 18.
• Tai Cha No. 8 (台茶8號): Early Assam hybrid (1930s). Classic malty-caramel profile, without cinnamon-mint notes. Dense, rich. More accessible.
• Yúchí Assam (魚池阿薩姆): Pure Assam tea — strong, “English” style. With milk and sugar — excellent. Most accessible.
• Taiwanese wild mountain tea (臺灣山茶): From Camellia formosensis. Rare, produced in small batches. Unique “forest,” grassy-floral profile. Collector grade.

In conclusion:

Riyuetan Hong Cha is a tea-discovery: once you try “Red Jade” with its incredible cinnamon-mint aroma — you will never confuse it with any other red tea in the world. Born from half a century of breeders’ patience, from earthquake tragedy and from Taiwanese farmers’ persistence, Hong Yu is living proof that true magnificence requires time.

On the shores of a lake whose eastern half resembles the sun and western half the moon, grows a tea that unites two bloodlines: the power of Indian Assam and the refinement of wild Taiwanese mountain tea. The result is something that exists nowhere else: the hot, spicy aroma of cinnamon, the refreshing coolness of menthol, and the ruby depth of liquor for which this tea was called “jade.” To try it is to touch the unique tea heritage of Taiwan, which cannot be copied or counterfeited.