At a glance: The most common incense fakes are oil-boiled, oil-injected, and chemically-soaked wood passed off as agarwood or sandalwood. The practical detection signals are burn behavior (white smoke and oil seepage vs black smoke), aroma on gentle heat (complex and sweet vs “perfume” or “burnt wood”), and the sink test for agarwood density.
Key facts: This is a buyer-intelligence reference, not a laboratory method. For definitive authentication, use a reputable seller and, where it matters, laboratory testing.
Key Takeaways
- The three common fakes: 煮油 (oil-boiling), 高压灌油 (oil-injection), 泡药水 (chemical/dye soaking).
- Signals: white smoke + oil seepage (real agarwood) vs black smoke (many fakes).
- A complex, sweet aroma on gentle heat is the hallmark; “perfume” or “burnt wood” is a red flag.
- The sink test works for agarwood density (沉香 = “sinking fragrance”).
- These are traditional heuristics — not laboratory proof.
The Common Fakes
| Method | Chinese | What it does |
|---|---|---|
| Oil-boiling | 煮油 | Boils ordinary wood in oil to add weight and scent |
| High-pressure oil injection | 高压灌油 | Forces oil into non-resinous wood |
| Chemical/dye soaking | 泡药水 | Dyes and scents non-resinous “white wood” |
| Substitution | — | Unrelated woods (Lauraceae, Burseraceae) with synthetic fragrance |
Detection Signals
| Signal | Real (tends to) | Fake (tends to) |
|---|---|---|
| Burn smoke | White smoke with oil seepage | Black smoke |
| Gentle-heat aroma | Complex, sweet, layered | “Perfume” or “burnt wood” |
| Room-temperature aroma | 奇楠 is aromatic even unheated | Synthetic has a one-note smell |
| Density | Resin-dense agarwood sinks (沉水) | Oiled wood may sink but smells wrong |
The Sink Test (Agarwood)
Because 沉香 means “sinking fragrance,” the classic density test is literal: does the piece sink in water? Resin-dense agarwood sinks; lower-grade wood floats. (See the grading guide for the full 沉水 system.)
Caveat: oil-injection fakes are designed to pass weight/density checks, so the sink test alone is not proof — combine it with the burn and aroma signals.
The Honest Limits
These are traditional buyer heuristics, accumulated in the Chinese agarwood market — not laboratory methods. A skilled counterfeit can defeat any single signal. The reliable route is:
- Buy from a reputable seller who names the species and origin.
- Use laboratory testing where value justifies it.
- Treat “too cheap for the claimed grade” as the strongest single signal.
The Author’s Take
Position: My contrarian experience: the strongest authenticity signal is not a burn test — it is the seller.
Reasoning:
- A vendor who cannot name the species, the origin, and the grade is already giving you all the information you need.
- The burn and aroma signals are a useful backup — but “what exactly is this, and where is it from?” is the honest shortcut.
This is the author’s editorial view and experience — not a verified fact.
Verification Notes
- The 煮油 / 高压灌油 / 泡药水 methods and the white-vs-black smoke, oil-seepage, and sink-test signals are drawn from Chinese specialist sources.
- These are presented as traditional heuristics, not laboratory standards.
- No health or medical claims are made.
See How Incense Is Made: From Wood and Resin to Stick and Coil for the full guide.
FAQ
Q: How can I tell if agarwood is real?
A: Combine several signals rather than relying on one. On burning, real agarwood tends to give white smoke with a slight oil seepage, while many fakes give black smoke. On gentle heat, real agarwood releases a complex, sweet, layered aroma, whereas a fake often smells like “perfume” or plain “burnt wood.” For density, resin-rich agarwood sinks in water — the classic 沉香 “sinking fragrance” test — but this alone is not proof. Most important is the seller: buy from someone who names the species, origin, and grade. See the grading guide.
Q: What is “oil-injected” agarwood?
A: Oil-injected agarwood is non-resinous, low-grade wood that has had oil forced into it under high pressure to add weight and a superficial scent, so it passes density and weight checks a buyer might use. The added oil is usually cheap, and the aroma is thin or “perfume-like” — nothing like the layered sweetness of genuine resin-rich agarwood. Because the oil sits in the wood rather than forming naturally, the piece may smell wrong on gentle heat and burn with a different smoke character. It is one of the most common fakes precisely because it defeats the sink test, so always combine it with burn and aroma checks. See the grading guide.
Q: Is the sink test reliable?
A: It is a useful density signal but not proof on its own. Resin-dense agarwood genuinely sinks in water, which is where the name 沉香 (“sinking fragrance”) comes from, and lower-grade wood floats — so the test can quickly rule out obvious low-resin pieces. However, oil-injection fakes are engineered specifically to pass weight and density checks, and some dyed or treated woods will sink too. A sinking piece can still be a fake, and a floating piece is not automatically worthless. Treat the sink test as one data point and always combine it with the burn smoke and the gentle-heat aroma before deciding.
Q: Why is fake sandalwood common?
A: True Santalum album sandalwood is scarce and expensive: the tree grows slowly, takes years to develop its heartwood oil, and has been heavily overharvested, so genuine material commands a high price. That price gap invites substitution — sellers pass off other sandalwood species, unrelated pale woods, or synthetic fragrance blends under the sandalwood name because the margin is large. Buyers who look only at the name or the low price end up with a copy. Confirming the species and origin, and accepting that real sandalwood costs more, is the practical defense. See the sandalwood guide.
Sources
- 本草纲目 — historical materia-medica record (traditional, not clinical).
- Chinese specialist/consumer sources on 沉香 authenticity checks (white smoke/oil seepage vs dyed fakes).
- Aquilaria malaccensis on GBIF — the botanical species behind most agarwood.
- Aquilaria in the CITES species checklist — agarwood is CITES-listed, which drives scarcity and substitution.
- Research synthesis: docs/research/agarwood-chenxiang-notes.md (R-001).
Related Resources
Natural next step: see the grading system fakes exploit in agarwood grading, or the species-substitution problem in the sandalwood guide.