Man finds 'mushroom-like' glob in beer

Brewery giant InBev is investigating a Sydney man's claim he found a foul-smelling mushroom-like object in a bottle of Beck's beer at an engagement party.

The man noticed something was wrong when he took his first swig from the bottle, his wife said.

"His beer tasted awful and he wiped off what looked like dirt from the bottle cap," the woman said in a post on viral news site reddit, under the username Seenbean.

"We go into the kitchen, pour the beer down the sink and something slipped out. I turned it over and it kind of looked like a mushroom and smelled a whole lot like s---."

The woman, who did not identify herself when contacted by ninemsn, said she had filed an official complaint with the beer's Australian distributor Lion Nathan.

But Lion Nathan said they were not responsible for the alleged contamination because it had been brought into the country by another retailer.

"We take all consumer feedback regarding our products very seriously and our local breweries have strict protocols in place to ensure the integrity of our products," a Lion Nathan spokeswoman told ninemsn.

"Upon further investigation we have determined this product was a parallel import not produced by Lion in Australia, meaning the consumer's best course of action is to return the product to the store it was purchased from."

A spokeswoman for Belgium-based beverages company AB InBev, which owns Beck's beer, said it was the first time they had received such a complaint.

"As soon as [the incident] was brought to our attention we immediately began working together with our local partners to investigate the source of the issue," spokeswoman Karen Couck said in an email

A food safety expert who analysed a of the mystery contaminant for ninemsn said he believed it would have been in the bottle before the beer was poured inside.

"This means that the 'glob' got in either at the glass company, in transport from the glass company, or in storage at the brewery," said Frank Vriesekoop, a senior lecturer at Harper Adams University college in Newport, England.

"Because I don't know what the 'glob' is, it is impossible for me to comment whether or not anyone could get sick if and when they consume this material."

He dismissed suggestions from users on the Reddit website that it could have been formed during a failed fermentation process.

He said large breweries usually run their beers through a number of different filters which would stop any large foreign bodies from entering the final product.

"These filters are usually made of a ceramic-type material, which means that it is unheard of that they can rupture in the process. This means that the suggestion that it is a plug of diatomaceous earth in this instance is also unlikely to be the cause," he said.

Mr Vriesekoop said Beck's breweries are some of the most modern ones in the world and that it was most likely a "very, very unfortunate once-off" incident.