How Oud Is Produced
The production of oud is a slow and often unpredictable process, shaped by biology, geography and traditional craft. Understanding how it comes about helps explain both its scarcity and its wide range in quality and price across the market.
Resin Formation
Oud begins with a tree of the Aquilaria genus, which under normal circumstances produces a pale, lightweight and largely odourless wood. Resin formation is triggered when the tree is wounded or infected, typically by a specific type of mould that penetrates the heartwood. In response to this stress, the tree produces a dark, aromatic resin intended to seal off the damaged area and resist further infection.
This process can occur naturally in the wild, often as a result of insect damage, lightning strikes, animal activity or other environmental stress. Natural infection is unpredictable, which is one reason wild agarwood with heavy resin content is considered particularly rare. In cultivated settings, growers have developed various inoculation techniques, including controlled wounding and the introduction of fungal cultures, to encourage resin formation more reliably and at a younger tree age than would typically occur in nature.
Harvesting
Once a tree is believed to contain sufficient resin, it is felled and the wood is carefully inspected. Not all parts of a tree will have developed resin, and even within a single trunk, resin distribution can be uneven. Skilled harvesters traditionally identify likely resin pockets by visual cues such as discolouration, weight and sometimes scent, carving away the lighter, resin-free wood to isolate the darker, infused sections.
This selective process is labour-intensive and requires considerable experience, since cutting away too much wood wastes valuable material while leaving too much reduces the purity and value of the final product. In regions where agarwood harvesting is regulated, there are often restrictions intended to protect wild tree populations and encourage sustainable cultivation instead.
Grading
Agarwood is typically graded according to several factors, including resin density, colour, aroma and the proportion of resin to plain wood. Denser, darker pieces with a higher resin content are generally considered higher grade and command greater value, while lighter pieces with less visible resin are graded lower. Grading practices and terminology can vary between producing regions and traders, and there is no single universal standard used throughout the industry.
Extraction and Distillation
For oud destined to become oil, the resin-infused wood is typically chipped or powdered and then soaked for a period before undergoing distillation, most commonly through water or steam distillation methods. This process can take many hours or even days, and it is repeated or adjusted depending on the desired characteristics of the final oil. The yield of oil relative to the raw wood used is generally very small, which contributes significantly to the cost of genuine distilled oud oil.
Some producers use hydrodistillation, where wood is soaked directly in water before heating, while others use steam distillation, passing steam through the wood to carry aromatic compounds into a condenser. The choice of method, along with soaking time, water quality and distillation duration, all influence the final scent profile of the oil produced.
Synthetic and Blended Alternatives
Given the cost and scarcity of genuine agarwood resin, a large portion of oud sold commercially today, particularly in mass market perfumery, relies on synthetic aroma compounds designed to mimic the scent of natural oud, sometimes blended with small amounts of real oud oil. These alternatives make oud-style fragrances more widely accessible, though they are generally considered distinct from genuine distilled agarwood oil both in composition and in the experience they offer.