Paperbark essential oil is a well-known product of Thừa Thiên Huế province. It is a must-have souvenir for Huế visitors. Huế paperbark essential oil is a heritage in terms of reputation and quality with the stellar production method since the Nguyễn Dynasty. Throughout the 350 years, 9 generations of lords and 13 generations of emperors, paperbark essential oil of Huế had always been in the list of tributes to Nguyễn lords and emperors . The legend has that the originators of Huế paperbark essential oil were lemongrass oilmakers of the North who followed Lord Nguyễn Hoàng to Thuận Hóa to reclaim virgin soil and started paperbark essential oilmaking on the foot of Phước Tượng pass in Lộc Thủy commune, Phú Lộc district, Thừa Thiên Huế province. The oilmakers here thus are regarded as masters of the profession. 

As emperor’s tribute, Huế paperbark essential oil was sold all over the Indochina in the 1930s and became a well-known product. It was the Tôn Thất royal clan, descendants of Prince Định Viễn (the sixth prince of Emperor Minh Mệnh), who laid the foundation for such commercialization by setting up over 3,000 distributors all over the Indochina  . 

Thanks to its uses and reputation, Huế paperbark essential oil has received many prestigious awards such as the Dragon Medal (1930); second place of Kim Khánh award and third place of Ngân Tiền award (1931); Honorary certificate along with a wooden statue in the Artisan’s Competition in Hải Phòng; First place of Ngân Tiền Award and Artisan’s Competition in Huế; Honorary certificate at the Scientific Artisan’s Competition in Hà Nội; First place at the Sài Gòn Women Fair. 

With time, the people of Huế continue the traditional profession of their ancestors, and their accumulated experiences and creativity have resulted in a high-quality product, satisfying healthcare needs of consumers in the new age. The switch from “cooking” method to distillation method allows the paperbark essential oil to have higher medicinal content, especially the Cineol (40-60%). 

The markets of Huế paperbark essential oil is the same as traditional paperbark essential oil markets, which consists of not only the local and domestic markets but also in countries of Asia, Europe and the Americas.  

Huế paperbark essential oil has a specific faint aroma (not too strong nor pungent). The aroma is long lasting, and the oil does not stick on the skin once evaporated. 

   

The peculiar quality of “Huế” paperbark essential oil is thanks to the plant in the geographical area being planted on Ferralsols and sandy soil. The soil has high Fe and Mg2+ content (Fe at 4.17 – 6.17 mg/kg, Mg2+ at 1.0 – 2.96 meq/100g). It is acidic with pH level at 3.25 – 5.57 and low on nutrition and humus (humus content at 0.78 – 4.13%). 

Thừa Thiên Huế has the highest rainfall in Viet Nam, averages at 2,500 to 3,800 mm annually, 1,500 to 2,000 mm higher than national average. However, the rain concentrates for a short time only, from September to February. From March to August which is the main harvest for paperbark, the number of rainy days is about 59 days with the average rainfall of 612 mm, significantly lower than other provinces such as Quảng Bình, Quảng Trị, Long An, and Tây Ninh. This is one of the reason for the high Cineol content in Huế paperbark essential oil. This is in line with researches by Khuất Thị Hải Ninh (2009, 2016) , which shows that low rainfall during dry season increases the essential oil amount and Cineol percentage, while high rainfall during rainy season decreases the oil amount and Cineol content in paperbark leaves. 

Paperbark is a sun-loving plant. Longer sunlight means photosynthesis activity also increases, while respiratory activity decreases. As a result, the plant can synthesize matters better, including Cineol. Annual average total hours of sunlight in Thừa Thiên Huế is 1,900 hours – suitable to the development of paperbark, and result in high quality essential oil. 

Aside from the natural conditions, the longstanding reputation and quality of Huế paperbark essential oil are also thanks to the method of production preserved for generations. Raw material harvest, distillation and heat treatment are the most important steps, directly affect the consistency and quality of paperbark essential oil. 

In the geographical area, from March to August, leaves from mature branches (about 30 cm long). The leaves must be thick, wide, have spicy taste and harvested from paperbark trees of at least 4 years old. Leaves are harvested twice on each tree, 3 to 4 months apart. 

The producers in the area especially emphasize on the distillation time, which lasts 4 to 5 hours from heat induction to completion. If the distillation is less than 4 hours, the essential oil will have inferior quality as the oil is not fully extracted from the leaves. If it prolongs for more than 5 hours, the oil will be spoiled by impurities. During the distillation, the temperature is strictly controlled. 

At first, the producers will induce high heat to boil the water quicker, then the heat will be stabilized at reasonable level of 100 - 120^oC. If the temperature is too high (over 145^oC) the liquid will pour into the distiller pipe, and resin will melt into the oil, reducing the quality. Moreover, high temperature will result in ester, Cineol in the oil being hydrolysed into acid an alcohol, adversely affect oil quality. On the other hand, low temperature (under 80^oC), while does not greatly affect oil quality, will lower the productivity. 

Geographical area: Communes of Phong Xuân,  Phong Sơn,  Phong An,  Phong Hiền,  Phong Hòa,  Phong Bình,  Phong Chương,  Điền Lộc,  Phong Mỹ,  Phong Thu,  Điền Môn,  Điền Hòa,  Điền Hương,  Phong Xuân and Phong Điền township of Phong Điền district; Communes of Lộc Bổn,  Lộc Thủy,  Lộc Tiến,  Lộc Sơn,  Lộc An,  Lộc Hòa,  Lộc Điền, thị trấn Lăng Cô and Phú Lộc township of Phú Lộc district; Communes of Quảng Lợi,  Quảng Vinh,  Quảng Thái and Sịa township of Quảng Điền district; Hương Thọ commune and the wards of Hương Văn and Hương Vân of Hương Trà town; Communes of Thủy Phù,  Thủy Bằng,  Phú Sơn, Dương Hòa and Thủy Phương ward of Hương Thủy town; Wards of An Cựu,  An Đông,  An Hòa,  An Tây,  Hương Long,  Hương Sơ,  Kim Long,  Phú Bình,  Phú Cát,  Phú Hậu,  Phú Hiệp,  Phú Hòa,  Phú Hội,  Phú Nhuận,  Phú Thuận,  Phước Vĩnh,  Phường Đúc,  Tây Lộc,  Thuận Hòa,  Thuận Lộc,  Thuận Thành,  Thủy Biều,  Thủy Xuân,  Trường An,  Vĩ Dạ,  Vĩnh Ninh and Xuân Phú of Huế city, Thừa Thiên Huế province. 

  

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