Styrax tonkinensis (STYRACACEAE)
The styrax genus is made of a group of decidious and evergreen shrubs and trees that grow in Northern and Southern America, Asia and Europe.
Siam and Sumatra benzoins are the two most important varieties cultivated for their gums.
They are tall and evergreen trees that can reach a height of 12 to 15m. They are characterised by long ovate citrus-like leaves and clusters of white flowers.
EXTRACTING THE TEARS
The resin that exudes from the bark does not occur naturally. It is secreted by numerous oleoresin ducts that are formed after the tree has received a severe wound.
The tree is axed or ‘tapped’ with traditional tools by making a V-shaped incision in the bark. The resin is a creamy fluid that starts collecting under the bark or oozes out
of the incisions. With time it takes a honey amber like tone and hardens into tear-shaped lumps which are collected 3 to 4 weeks after the tree has been tapped. The tears are then cleaned, sorted and graded into quality groups.
The tree needs to be no less than 7 years old before the process of tapping can start. The first 3 years yield the best quality gum. On average a tree produces 1.5 kg a year. Production carries on for 10 to 12 years after which the tree is cut down and the remaining gum scraped.
There is not such thing as benzoin essential oil. It is actually a resinoid which is the result of a solvent extraction of the gum. The solvent used is alchohol which is evaporated to leave the pure fragrant resinoid on one side and the residue tears from which the fragrant compounds have been extracted on the other. The resinoid is a dark brown solid sticky ‘mass’, which smells delicious but is totally unworkable to the Aromatherapist.
Typically it is diluted with Dipropylene glycol to different ratios to offer resinoids of various viscosity and mobility.
Benzoin growing in Sumatra and Java is extracted from Styrax benzoin whereas Siam Benzoin comes from Stryrax tonkinensis which grow in Thailand and Laos.
Sumatra benzoin contains 18 % benzoic acid, about 20 % of cinnamic acid and 1% of vanillin.
The chief constituent of Siam Benzoin is benzoic acid (32%.) along with 2% vanillin but no cinnamic acid. Perhaps this is the lack of cinnamic acid that makes Siam Benzoin considered superior by perfumers.
This is the variety that Materia Aromatica stock.
– Respiratory system:
Benzoin works as a mild expectorant and is useful with conditions such as bronchitis, cold & fly symptoms, sore throats. It also helps with asthma along side frankincense and bergamot
– Arthritis & rheumatism
– Skin conditions
Its antiseptic & anti-inflammatory properties are useful in cases involving eczema, acne, red and inflamed of the skin, chapped skin, cuts and bruises.
– Nervous tension and stress related complaints
Benzoin is also said to be mildly irritant to the skin. It is recommended to do a skin test before applying it. Do not use neat, always dilute in a carrier oil before use.
Benzoin will blend well with a number of other essential oils
– Flowers such as geranium, jasmine, neroli, rose, ylang ylang, tuberose,
– All the citrus oils
– The woods and woody fragrances: cypress, juniper, cedarwood, sandalwwod, laurel
– Also frankincense, myrrh, spikenard