Three simple field tests reveal how much resin agarwood holds: water immersion (denser, resin-rich pieces sink), hot-plate or steam heating (stronger, sweeter smoke signals higher saturation), and visual inspection of black-brown “tiger-stripe” veining. Together these checks estimate grade and predict distillation yield before you commit to a lab or a purchase.
Why does resin content matter before you distill or buy?
Resin is the whole point of agarwood. The fragrant oil that buyers in the Gulf and China pay for lives inside the dark resin the tree deposits after infection or stress — not in the pale background wood. Higher resin content correlates with stronger fragrance, higher density, and a higher grade, so estimating it early protects both your money and your still.
For a distiller, resin content is a yield forecast. Low-resin kemedangan gives thin, weak oil; heavily saturated gubal produces the deep, long-lasting oud that commands the top of the price band. Before a batch reaches a professional oud oil distillery in Bali, a few minutes of field testing can separate material worth soaking for weeks from material better sold as chips or powder.
The grade-dependent price band shows why the stakes are high. Plantation agarwood chips run roughly USD 500-7,000 per kilogram depending on grade, and oud oil runs about USD 30,000-80,000 per kilogram (as of 2026, indicative, with a final quote confirming grade and scope). A field test that mistakes B-grade for Super A can cost thousands.
How do you run the water immersion (sink) test?
The water immersion test is the oldest and simplest density check. Drop a clean, dry piece into a glass of room-temperature water and watch what it does.
- Sinks fast: high resin saturation; the piece is denser than water. This is the signal graders associate with Super grades.
- Sinks slowly or hovers: moderate resin; mid-tier material.
- Floats: low resin content, or a piece with trapped air pockets.
Density is the first of three objective criteria graders use, and sinking is the shorthand for “resin-rich.” Test at least two or three fragments from the same lot, because a single chip can mislead — a hollow cavity or a dry surface skews the result. Weigh the piece dry first if you can; consistent sink-plus-weight readings are far more trustworthy than one dramatic plunge.
What does the hot-plate or steam test reveal?
Aromatic intensity is the second criterion, and heat is how you read it. Shave a thin sliver, place it on a warm hot plate or hold it in steam, and smell.
Higher-resin agarwood releases a stronger, sweeter, more layered smoke that lasts longer as the oils volatilise. Thin, faint, or quickly fading smoke points to low saturation. Genuine oud develops in waves — an initial sweetness, a resinous middle, a woody base — while low-grade or adulterated material smells flat or gives off an acrid, plasticky note.
Keep the heat gentle. You want to warm the resin enough to release fragrance, not scorch the wood, which produces a burnt smell that masks the true profile. This test is subjective, so calibrate your nose against a known reference piece whenever possible.
How do you read tiger-stripe veining and other visual cues?
The third criterion is resin saturation you can see. High-grade agarwood shows black-brown “tiger-stripe” veining — irregular dark resin threaded through lighter wood — not a uniform, plastic-like black. A suspiciously even, glossy black surface often means the piece was dyed, oiled, or pressed with resin filler.
Look for these visual markers:
- Depth of colour: dense dark veining across the cut face signals heavy deposition.
- Pattern irregularity: natural resin follows the grain unevenly; fakes look painted on.
- Weight in hand: resin-loaded pieces feel heavier than their size suggests.
- Oily residue: genuine high-resin wood can leave a faint oily film, not a wet paint smear.
| Field test | Criterion measured | Higher-resin signal | Equipment |
|---|---|---|---|
| Water immersion | Density | Piece sinks quickly | Glass of room-temperature water |
| Hot-plate / steam | Aromatic intensity | Strong, sweet, long-lasting smoke | Hot plate or steam source |
| Visual veining | Resin saturation | Irregular black-brown tiger-stripe veins | Good light, magnifier |
How do the three tests combine into a field grade?
No single test is decisive. Density, aroma, and veining are meant to be read together, and Indonesian trade practice recognises this — chips are commonly sorted across about nine grades, with the key tiers Super A, Super B, Super C, and Sabak, while the remaining grades mostly denote wood size and resin quantity rather than fragrance alone.
| Water test | Aroma | Veining | Likely field tier |
|---|---|---|---|
| Sinks fast | Strong, complex | Dense irregular veins | Super A / Super B |
| Sinks slowly | Moderate, pleasant | Visible veining | Super C / Sabak |
| Floats | Weak or acrid | Sparse or uniform | Low-resin / kemedangan |
Remember that these grading systems are industry conventions that vary by region and tradition; they are not an official Indonesian national standard, so a “Super A” from one broker may not match another’s. Origin adds context too: wild agarwood from Papua and Maluku is regarded as typically superior, and East Kalimantan — notably Apau Kayan — is a documented historical wild-sourcing area. TRAFFIC’s field report “Heart of the Matter” recorded super grade A from Apau Kayan at about IDR 1,250,000 per kilogram back in 1997, then roughly USD 450 per kilogram, a reminder of how long this grading vocabulary has been in use.
What are the limits of field testing?
Field tests estimate; they do not certify. Water can be fooled by air pockets, noses tire and disagree, and skilled sellers dye, oil, or compress low-grade wood to fake veining and weight. Treat these methods as a first filter, then confirm anything you plan to buy in volume with laboratory gas-chromatography analysis of the oil.
There is also a legal filter that no field test replaces. Most Aquilaria and Gyrinops species sit under CITES Appendix II, so legal export requires a CITES permit and a BKSDA recommendation, subject to a Non-Detriment Finding; Indonesia’s 2024 NDF set a wild Aquilaria malaccensis quota of 24,110 kilograms. CITES paperwork also separates source code W (wild) from P (plantation), and plantation material is generally easier to permit and more sustainable. Confirm current requirements with the CITES Management Authority (Indonesia) and your import country before shipping — this is a sourcing and information resource, not a permit authority.
Frequently Asked Questions
Can the water sink test alone tell me the exact agarwood grade?
No. Sinking confirms high density and likely high resin, but it cannot separate Super A from Super B or catch a dyed fake. Density is only one of three objective criteria — combine the immersion result with the hot-plate aroma test and the tiger-stripe veining check, then verify high-value lots with laboratory oil analysis.
Does soaking agarwood for the sink test damage it or hurt distillation?
A brief immersion in room-temperature water does not harm sound chips; agarwood is soaked for days before distillation anyway. Keep the test short, use clean water, and dry the pieces afterward. Prolonged soaking of already-processed or powdered material can encourage mould, so test with whole fragments rather than fine powder.
Why do some resin-rich chips still float during the immersion test?
Trapped air is the usual reason. A piece with an internal cavity, a dry crusted surface, or an irregular shape can hold enough air to float despite heavy resin. Test several fragments, break suspect pieces to expose fresh surfaces, and weigh them dry — consistent sink-and-weight readings are far more reliable than one floating chip.