Let it be known that I am officially enamoured with oakwood absolute.
I recently received a sample of this amazing material from French essential oils and natural extracts producer Biolandes. Having heard roumers of a rare and seemingly mystical essence romantically created from aged oak barrels discarded by French wineries, I came across a real-life reference to it as a newly released product in the October 2010 Perfumer and Flavorist magazine.
As far as I can tell, Biolandes is the only manufacturer of this true oakwood (Quercus robur) absolute – please correct me if I’m wrong and you know of another. It is actually made from new oakwood and not from used barrels but you would not guess that from the aroma and I had to confirm this fact with the Biolandes sales rep as I was unbelieving that such a richness could come from the new wood alone.
There are a few producers of an oak bark extract which is used to provide a whiskey or aged brandy note to alcoholic beverages and there is also an oak bark powder dietary supplement. The extract is created by seeping pulverised oak bark in hot water – a different process from the absolute and I imagine these products would not have the depth and complexity of the absolute.
I am at a complete loss as to why oakwood absolute is not being used more frequently by perfumers around the globe – particularly by the indie / artisan perfumers. It is not overly expensive and there are no particular safety concerns that I can find. Perhaps it just is not well known out there, being relatively new – hopefully this blog entry will go small way towards rectifying that.
The absolute is brown, viscous and opaque and is supplied diluted to 50% with triethyl citrate (TEC) – to make it more useable. When opening the vial and taking a smell of the pure material you are immediately transported to a wine cellar in the Bordeaux region of France, surrounded by the old casks and the fermented smell from years of red wine spilled on the stone floors. There is a mustiness there along with woody notes and warm, sweet raisins and vanilla. Smelling this stuff provides an immediate insight into the flavours and aromas that oak imparts to wine and why the type and quality of the wood used in the casks is so important.
To delve a little into the chemistry involved, the main volatile compounds in oakwood that are present in the absolute and also impart their aroma and flavour into wines are:
cis- (and trans-) oak lactone – responsible for the majority of the vanilla and coconut-like aromas. These lactones vary greatly between the types of oak selected and are affected by the seasons and differing growing regions.
Guaiacol and 4-methylguaiacol – these have a smoky / spicy / vanilla aroma and are created by and vary depending on the levels of toasting the cask staves are subjected to before the wine is stored. These chemicals are probably not actually present within the absolute as the Biolandes sales rep assures me that the oak used to produce the absolute is not toasted before-hand. But these ingredients are extremely important to the vintner.
Vanillin – Vanillin is the main flavour compound in natural vanilla and is also present in oakwood. The level of vanillin imparted into wines stored in oak barrels decreases over time as it is transformed by yeast metabolism during fermentation. Vanillin concentration can be reduced considerably if primary fermentation is carried out in the barrel.
The oak absolute has a nice vanilla / coconut note due in part to the vanillin content.
Furfural and 5-methylfurfural – once again, these sweet, caramel / butterscotch smelling materials are mainly a result of the toasting of oak and may not be important in the scent of oak absolute, but are obviously important to the vintner.
Syringaldehyde – has an aroma described as sweet, chocolate, woody, tonka, grape. Syringaldehyde is interestingly used by some insects as part of their chemical communications system and plays an important role in the over-all impression of the oak absolute.
Biolandes’ oakwood absolute begins life as by-product oak chips that the company purchases from the famous cooperage firm Dargaud & Jaegle. The oak used has been felled under National Forest Office control, from October to April when the sap is down and has been selected from 17 selected stave suppliers from around the region. The volatile components are extracted from the wood chips using a light hydrocarbon (hexane, I believe) and further processed to arrive at the final thick, dark, viscous and fragrant liquid.
Artisan perfumer Laurie Erickson has used oakwood absolute to good effect in the Sonoma Scent Studio perfume named
To Dream where the oakwood plays a supporting role to the main floral theme.
I have been working on a perfume for Evocative Perfumes that instead moves the oakwood to centre stage supported by incense, rose, woods and a warm smoky ash. The original concept for this perfume was to simply enhance and adorn the natural qualities of the oakwood and was inspired by my visits to the local cellar doors of the Barossa wine region here in South Australia with their huge old barrels, open fireplaces in the winter and long, polished counters.
As development has continued over the last couple of months however, the overall effect of the perfume has become progressively softer and warmer and my partner now says that it invokes more of a spiritual feeling in her, in fact the words Gregorian chant came to mind just this afternoon. It feels right, but it seems a little trite to use that expression as a name for the fragrance – I don’t know, we’ll see how it goes.