A video showing a completely sober policeman eating hot cross buns before blowing a breathalyser and coming up as intoxicated on the reading has Twitter in an uproar, but a simple Google search quickly reveals the reasons for this strange occurrence.
In January 2018 the phenomenon of the “alcoholic hot cross buns” went viral in Australia after a trucking company named “Pilbara Heavy Haulage Girls Inc.” posted a video very similar to the one generated by the anonymous police officer here in South Africa.
Just like in the local video, a trucker in the video blew into a breathalyzer to produce a 0.000 reading, demonstrating that she had not consumed any alcohol, before taking a bite of a hot cross bun, swallowing and then immediately recording a reading of a 0.018 BAC reading.
Naturally, British tabloid papers then blew the video out of proportion by claiming that eating hot cross buns can get you arrested. This has been a similar reaction by some of South Africa’s top “influencers” who have used to the new video to call for investigations and craft conspiracy theories.
A quick Google search, however, will uncover a page on Snopes.com that explains the phenomenon and how to avoid it.
“A well-established relationship exists between the amount of alcohol in one’s blood and the amount of alcohol in respired air from the lungs,” the site explains before adding that the breathalyser devices’ instruction manuals indicate that they should not be used on subjects for 15 to 20 minutes after they’ve eaten due to the presence of “mouth alcohol”.
“Mouth alcohol” the site explains, is caused by the yeast in pastries such as hot cross buns, converting sugar into carbon dioxide and ethanol, which is then transferred into the mouth and registered by the breathalyser as respired alcohol. Due to the fact that the device is searching for a known ratio of alcohol from the lungs, even a small amount in the mouth can throw off the reading enormously, which is what happens in the videos.
“Because this alcohol was physically located in the woman’s mouth at the time of testing, however, it was not representative of her blood alcohol content, which would still accurately be described as zero. The addition of more hot cross buns … would not increase her blood alcohol content in any way, and a properly administered test, following the appropriate waiting period, would demonstrate this reality,” the site concludes.