If you have experienced Oud oil before, you would probably have a mix of feeling about it. From the moment of opening the cap, some were so fecal that made you close the cap of oil vial immediately. In the other hand, some smelled divine. The reason mainly lied on raw material (woodchip) or distillation technique. For example, soaking the agarwood dust/chip/ powder for too long could develop a different type of fungus/ mould, making its scent profile changed. Sometimes, and it is quite common that smell of decomposition wood which is skanky could be detected as a result of over soaked wood. Some likes this, others do not., Another factor, high distilling temperature which could create a burn note of the oil.
High-end Oud oil is closely monitored to ensure its quality. Its scent profile is complete which is sufficient to enjoy on its own. Blending it with other oil is not recommended unless the perfumers know what they are doing. It has different texture from golden to black which always in liquid form.
Low-end Oud, or what ever remaining on the pot after the premium was taken out, appears to be waxy.
Again, every batch could different. You might ask "What are you going to do with wax Oud?"
The scent profile is "not too bad". It smells fecal, armpit at first but after several minutes on skin, it becomes wearable, the woodsy Oud could be detected. This is where the cosmetic industry gets in.
With the right chemical, the armpit smell could be got rid off completely to make soap and skin care cream. Please do not be surprised at soap are made from cooking oil too. There is nothing wrong about this.
This was Oud is cheap and great for making candles.
Feel better? Yes ! But how do I distinguish or recognise these wax Oud oil?
At room temperature, you could give oil a shake to check if there is any deposit in the bottle. From my experience, these wax oil are in solid state at circa 20 degree Celcius.
Please note there is nothing wrong with these oil as they serve very different purposes from the premium one and having their own market. You do not like chicken feet and think it is appalling but it was one of the most frequent ordered dish in Yum Cha.