The 45-Day Shade-Dry Process: Why Phu Van Huong Rejects Heat Ovens

In an era defined by the mantra “speed is life,” most incense manufacturers race to invest in high-capacity convection heat ovens. By subjecting wet incense to temperatures between 60°C and 80°C for just 8 to 12 hours, millions of sticks are rendered brittle and ready for shipment. This process maximizes floor space, accelerates capital turnover, and minimizes labor costs.

However, at the Thuong Dat artisan workshop, Hai Phong, Vietnam, we have remained steadfast for years in going against this trend with a process that might seem “irrational”: 45 days of patient, cool-wind shade drying. Why is this patience the vital soul of a superior agarwood incense?

Heat Ovens: The Silent Destroyer of Precious Agarwood Oils

Natural Vietnamese agarwood (Aquilaria oud) contains over 150 volatile organic compounds. The most delicate, sweet notes—such as Agarofuran and light Sesquiterpene derivatives—begin to evaporate at temperatures as low as 38°C–45°C. When incense is placed in a 70°C oven, the high heat forces these precious oils to evaporate into the atmosphere. The remaining heavy oils are pyrolyzed within the wood fibers, turning the incense into a dry, charred stick that emits a burnt, acrid odor rather than the natural, honeyed sweetness of pure agarwood.

The Mechanism of ‘Natural Moisture Release’

Our shade-drying process at the Hai Phong workshop is designed based on a profound understanding of cellulose fiber and botanical essential oil mechanics:

Zero Direct Sunlight: Incense is meticulously arranged on breathable bamboo racks in a cool, shaded room, completely avoiding ultraviolet (UV) rays that degrade aromatic molecular bonds.
Natural Convection: A low-power fan system provides constant, gentle airflow, simulating a natural autumn breeze and maintaining a stable room temperature below 26°C with strictly controlled humidity.
Core-to-Surface Moisture Release: Moisture in our 2.2mm–2.5mm coreless incense sticks evaporates at an ultra-slow rate. The natural Litsea glutinosa bark binder shrinks uniformly, resulting in a firm, flexible stick that is resistant to warping or cracking.
Locking in the Essence: As moisture departs gently, the natural agarwood oils condense and bond deeply into the micro-vessels of the Dó Bầu wood, ready to bloom the moment they meet the flame.

A Comparison of Drying Methods

Technical Criteria	Industrial Heat Oven	45-Day Shade-Dry (Phu Van Huong)
Completion Time	Super-fast: 8 to 12 hours.	Artisanal: 40 to 45 days of patience.
Oil Preservation	50% – 70% loss of light, sweet compounds.	Preserves > 98% of natural honeyed notes.
Flexibility	Brittle, prone to breakage.	Firm, flexible, and naturally smooth.
Aroma Profile	Burnt wood, dry, bitter aftertaste.	Deep, sweet, warm, and silky smooth.