New study on the long term stability of thujone

For many years, proponents of the Czech absinth ideology (affectionately known as 'thujone hypers') have argued that Dr. Arnold's estimations of 260 mg/l of thujone in pre-ban absinthe is correct. They've used the argument that the chemical analysis of existing samples of pre-ban era absinthes would be meaningless, since the data doesn't take into account what the 'original' thujone levels were, solely what is remaining. They've gone on to state that thujone isn't chemically stable, and that levels of thujone must have decreased as the bottle aged. So a bottle of pre-ban absinthe which might measure in at 20 mg/l now, might have had 100 mg/l back when it was first bottled.

These arguments have always been countered by absinthe historians such as myself, Alan, and many others that:

1) Thujone doesn't readily come over into the distillate. It's one of the last components to come over. If the distillation process is cut at the right time, very little thujone should carry over.

2) Absinthe's alcohol level should act as a stabilizing factor. Long term storage shouldn't affect thujone levels.




Following on the heels of a groundbreaking thujone study last year, now there is yet another scientific study to debunk many of the myths that were supported by the esteemed Dr. Arnold.

Last year's study focused on analyzing current thujone levels in both existing pre-ban samples as well as several brands that are currently produced. This study showed that many of the brands tested (including almost all of the pre-ban samples) would fall below either EU or US thujone limits.

The current study was aimed at addressing the 'thujone hyper's' argument that the thujone in vintage bottles would have degraded. According to the abstract:


"Research was conducted to ascertain whether analyses of vintage absinthe samples represent their original composition in the early 1900s. Absinthe stored in traditional green glass bottles and irradiated with ultraviolet light for up to 200 h exhibited unchanged composition. Samples stored in clear glass exhibited an 18% reduction in beta-thujone content and a concurrent decoloration. These experiments indicate the stability of thujone in vintage absinthes, as these were stored in green glass bottles. The preserved color of the preban absinthes subjected to analysis indicates that no significant light exposure occurred throughout the duration of storage, and therefore provides indirect proof that no loss of terpenes occurred. The stability of absinthe was further demonstrated through the reanalysis of samples from 2001-2005, which exhibited no changes in thujone content as of 2008. A previous evaluation of preban absinthe was therefore valid and not confounded by significant thujone deterioration over time."

The importance of this new study cannot be underestimated. Not only does it support the arguments of traditional absinthe historians, it also is a huge blow to those unscrupulous marketers out there who use 'historical' thujone levels as the most important quality of their brand.

How will those marketers respond? Here are a few of my predictions:

1) Since they don't have any real scientific or legal basis to refute the studies, they will use internet forums and blogs to make derisive comments and ad hominem attacks, either going under the guise of anonymity or using fake names.

2) They will continue to use the 'don't believe the science, just trust us' argument. This is the same as the 'we have no proof because ALL evidence throughout the entire world was destroyed during the Communist regime' argument.

3) They will claim that the report is biased, even though it was peer reviewed, and published in a well known journal. Since they don't have any current, concrete scientific proof (other than flawed estimations, such as that of Arnold), they might try to discredit the new information.

4) They will possibly try to distance themselves from their previous claims by reinventing themselves, creating new histories for their brands, and subtly changing their marketing information to reflect the new lower limits that are acceptable in the EU and in the US. There is already a boatload of documented evidence that some brands have done this.

Yours in absinthe,


Brian