Natural Characteristics

Benzoin Siam Gum (also known as white lac or Styrax gum) is a valuable raw material used for producing fragrance fixatives in the perfume industry, for extracting benzoic acid, and for applications in medicine and industry.

The Benzoin tree, scientifically known as Styrax sp., belongs to the Styracaceae family. It typically grows up to 15 meters tall. Young leaf buds are covered with fine, pale yellow hairs. The leaves are alternately arranged, 6–15 cm long and 2–2.5 cm wide, with entire, ovate blades that are rounded at the base and taper to a pointed tip. The upper surface of the leaf is light green, while the underside appears white due to dense fine hairs.

The tree produces small, fragrant white flowers arranged in clusters (panicles). Its fruit is spherical, 1–2 cm in diameter, covered with star-shaped hairs, and retains a persistent calyx at the base. The flowering season is from May to June, and the fruit ripens from September to October.

In Vietnam, there are four recorded species of the genus Styrax:

• Styrax tonkinensis Pierre

• Styrax benzoin Dryand

• Styrax agrestis G. Don

• Styrax annamensis Guill.

Among these, Styrax tonkinensis is the most common. It grows naturally in midland forest areas, especially in swidden fields and upland farms in provinces such as Hoa Binh, Ha Giang, Tuyen Quang, Lao Cai, Vinh Phuc, Lai Chau, Son La, Nghe An, Ha Tinh, and Thanh Hoa.

3 Benzoin Grades

Benzoin Siam gum is commercialized after a thorough cleaning and grading process, which categorizes it into three grades based on fragment size:

• Grade 1: large resin pieces

• Grade 2: medium pieces

• Mix Grade: mix between grade 1 and grade 2

Production is typically distributed as follows: 30% Grade 1, 30% Grade 2, and 40% Grade 3. These grades do not significantly differ in chemical composition; variations are primarily due to the physical sorting process. The grading can affect the product’s color during storage at room temperature, with tones ranging from beige to brown.

                  First grade                                                           Second grade                                                       Mix grade

The resin has a distinct vanilla aroma, is insoluble in water, and readily soluble in ethanol. When processed for export, Benzoin Siam gum appears as opaque, grainy, almond-shaped fragments measuring a few millimeters up to 30 mm, with a white to pale yellow hue.

Over time, and with exposure to ambient conditions, the gum may soften and clump into a reddish-brown mass. Surface discoloration occurs due to oxidation, though the interior typically retains its original pale yellow-white color.

In addition to Benzoin Siam, another resin type known as Benzoin Sumatra is derived from Styrax benzoin Dryander and Styrax paralleloneurum Perkins. These resins differ in species, geographic origin, and chemical profile. The term “benzoin gum” may refer to either resin type or a blend of both.

Siam benzoin is rich in benzoic acid and its esters, including coniferyl benzoate and benzyl benzoate, whereas Sumatra benzoin contains mainly cinnamic acid and its derivatives like coniferyl cinnamate and cinnamyl cinnamate. Both varieties contain vanillin, contributing to the resin’s characteristic vanilla scent—especially prominent in the Siam type.

Usable Part

Benzoin resin (also known as white lac, Styrax resin, or Benzoin Siam) is a natural resin exuded from the trunk of Styrax trees and allowed to dry naturally. The resin appears as irregular, separate lumps in white, pale yellow, or light reddish color. It has an opaque, brittle texture and can be scratched with a fingernail. When broken, the fracture surface resembles wax, with a pale white color that gradually turns brown over time. It emits a characteristic vanilla-like fragrance, with a mild taste followed by a pungent and slightly spicy aftertaste.

Extraction Method:
Trees aged between 5–10 years are selected. Incisions are made into the trunk and branches to induce resin flow. The resin is allowed to dry naturally before being harvested. Harvesting typically occurs at the end of autumn or during the winter season.

Quality Indicators:
Benzoin resin contains more than 50 different compounds, including:

• Free benzoic acid: 26.13%

• Vanillin: 1.38%

• Benzyl benzoate: 4.24%

The resin is almost insoluble in water, partially soluble in ether, and completely soluble in alcohol.

Dien Bien Agri is a trusted supplier of high-quality Benzoin Siam Gum, harvested and processed naturally to meet strict standards for pharmaceuticals, food, and export industries.

Read more about Benzoin here