Rather than having an intrinsically bad odour, the chemical that makes wine smell ‘corked’ is preventing normal smell signals from reaching the brain, finds a Japanese study.

The discovery, made in newts, also fits with smell tests done on human volunteers, according to a report in the Proceedings of the National Academy of Sciences.

The effect of TCA (2,4,6-Tricholoroanisole), the chemical culprit in corking, on smell receptors was being investigated by Dr Hiroko Takeuchi and Professor Takashi Kurahashi and colleagues of Osaka University, Japan.

The researchers had expected to find olfactory (smell) receptor cells in the newt that could detect TCA, but they couldn’t find any.

“We applied TCA to more than 100 receptor cells … but we didn’t see any excitation,” says Kurahashi.

Meddling with membranes

Instead, to their surprise, they found the chemical inhibited the firing of the newt olfactory receptor cells as they tried to pass messages on to the brain. This means that, regardless of the odour the cell detects, it can’t forward the information.