KEY POINTS:
Sarah Ferguson had barely put the glass to her lips when she realised something was wrong.
It was clear that what she had sipped was not the mulled wine she had ordered at the Queenstown bar.
"So I spat it out across the counter," Ms Ferguson told the Herald.
"It was reacting with your lips ... it was burning. It didn't really taste of anything. It just burnt your mouth like a bad soup burn. But it was all through your mouth and on your lips. It was so instant ... you had no idea what was going on."
For hours the burning sensation continued.
Ms Ferguson had been mistakenly served a poisonous dishwashing liquid instead of wine.
After Old Man Rock Cafe employee Bethany Sim also tried it and became unwell, both women were taken by ambulance to hospital for treatment. Ms Ferguson spent the night there.
The operator of the cafe, Chico's Restaurant Ltd, this week pleaded guilty to selling food containing sodium hydroxide which caused injury in July last year.
It was revealed that a mulled wine container stored at the cafe had been mistakenly filled with the detergent.
The liquid had been delivered in wine containers and the two products were then mixed up.
The bar operator was unavailable for comment yesterday. A sentence is due next month.
Ms Ferguson, a primary school teacher, says she is just glad the matter is drawing to a close.
She realises if she had swallowed too much of the detergent, things could have been far worse.
"The doctors did say half a glass and it wouldn't have been a good result."
Bruce Robertson, of the Hospitality Association of New Zealand, said the event was an "extraordinarily rare occurrence".
More than 100 million drinks were served around the country each year with few problems, he said.
