Drivers across the region are being warned to be cautious when consuming their favourite Easter treat.
The yeast in hot cross buns can ferment its various sugars enough for ‘alcohol’ to register on a passive roadside alcometer test.
However, this does not mean it would put a driver over the limit, following further breath analysis procedures.
Last week, a Pilbara truck driver, Heather Jones, blew 0.018 on an alcometer after a mouthful of a such a bun.
Her video went viral on social media, warning other truck drivers about her results. For a professional driver, such as a truck driver, the legal blood alcohol limit is 0.02.
Inspector Alison Brennan of Hume Police District confirmed that foods and substances other than alcoholic drink could register on the passive roadside breath test device.
She explained how such a situation could occur.
“In training to become a breath analysis operator, we test all sorts of stuff,” she said, “from mouth wash to garlic to all sorts of things, to see if they will register.
“There are foods and substances that can give a reading on a passive roadside test, but this is exactly why we have these procedures so there can be no doubt,” she said.
The procedure is a passive test using the alcometer, where a driver speaks into a hand-held device.
If the alcometer indicates that alcohol is present, the police then attach a tube to the hand-held device to get a sample of air from the driver’s lungs, not their mouth.
At that point, the ferment of a hot cross bun, for example, should not register an alcoholic reading.
However, if alcohol was present and over the legal limit, the police would then detain the driver and attend the nearest police station.
At the police station, a 15-minute observation period should ensure no residual mouth alcohol in a reading.
The driver would then be tested on the breath analysis machine, Inspector Brennan said, adding it had “a margin of error so negligible as to be irrefutable”.
Other positive readings in a passive roadside test could be caused by alcohol-based hand wash, an inebriated passenger breathing heavily, strong perfume, or liquor-flavoured desserts.
But as with the hot cross bun, these should not register beyond the initial passive breath test on the roadside.
Brewer Andy Orrell, of Hairyman Brewery and 30 years’ experience, explained the hot cross bun finding.
He said it was likely the baking yeast had the potential to consume the sugars, which had started fermentation.
The yeast could have fermented the sugars in the milled flour, the fruit, and the sugar glaze, he said.
“The sugars have been fermented by the yeast, just like beer would have,” he said.