Vinegar – once used by our grandmothers to clean the home – is hip again.

A new generation is squirting it around their kitchens and bathrooms, eager to use a cheap and green alternative to the cleaning products on the supermarket shelves.

Vinegar is certainly inexpensive, non-toxic and biodegradable. But does it really kill household germs?

The answer is a qualified 'yes'. It's not as effective as commercial cleaners but it's still a useful disinfectant.

How does it work?

Vinegar – be it white, malt or rosemary-infused – is about 5% acetic acid. It's the acid that kills bacteria and viruses, most probably by denaturing (chemically changing) the proteins and fats that make-up these nasties.

When US researchers pitted commercial cleaning products against alternatives like vinegar and bicarbonate of soda, they found that neat vinegar killed a range of household pathogens.

Overall, vinegar did slightly better than bicarbonate of soda, but neither killed as well as commercial products.

The science tells us that vinegar will kill off the flu virus. As part of research aimed at preparing us for a flu pandemic, UK researchers found that malt vinegar, as well as bleach and washing up liquid, inactivates the flu virus. It also works to neutralize bacteria causing stomach and gut issues like diarrhea.

However, it won't touch some types of salmonella, which can transfer from raw meat to chopping boards and onto other foods to give us food poisoning.

The bottom line

When it comes to cleaning house we need to remember to keep it simple, says Professor Peter Collignon, an infectious diseases physician at the Australian National University's Medical School.

Rather than concentrating on disinfecting or killing the bugs, we should focus on cleaning with hot soapy water and good old-fashioned elbow grease to physically scrub away organic material.

"You've got to clean the surface first and that's usually enough. Then you have to ask yourself whether you need to disinfect at all," he says.

"For the kitchen sink, for example, you probably don't need anything except cleaning."

However, that dirty chopping board might warrant disinfecting – but only after you've given it a good scrub with hot, soapy water.

It's only the act of rubbing and scrubbing a dirty chopping board that can break down the slimy matrix around certain types of salmonella, allowing the disinfectant to then get to work.

As for commercial cleaners, Collignon says we don't always need the level of disinfection in the home that these products provide.

"We over-use chemicals," he says. "Instead of using one unit, we use 1000 units, and the benefits are marginal."

"All of us would like to use a magic potion so that we don't have to use the elbow grease. But that's a false premise."Professor Peter Collignon, infectious disease physician at the Australian National University's Medical School