Let's put this to bed: an expert ruling on the 5-second rule

UQ Mythbusters

A cupcake with blue icing is lying upside down on the floor after being dropped

Image: Adobe Stock/New Africa

Image: Adobe Stock/New Africa

Let's put this to bed: an expert ruling on the 5-second rule

UQ Mythbusters

By Britt Wilkins

A cupcake with blue icing is lying upside down on the floor after being dropped

Image: Adobe Stock/New Africa

Image: Adobe Stock/New Africa

When it comes to food safety, guesswork is not the way to go. UQ Mythbusters is back at it again – this time we’re holding our nose and peeling back the wrapper on some classic furphies about what you should and shouldn’t do when preparing food in the kitchen.

You might be surprised by how many of these have you hoodwinked!

Mark Turner is a Professor of food microbiology at UQ and serves as a Deputy Head of the School of Agriculture and Food Sustainability. When we reached out to him with a list of ick-inducing food myths he said that these issues were “very close to my research – and my heart”.  Suffice it to say, he’s the man for the job.

Pop on the kitchen gloves and let’s get into it.

Key points:

  • The 5-second rule officially debunked – into the bin it goes!
  • Do not rinse the raw chicken – repeat, do NOT rinse the raw chicken.
  • If it smells fine and looks fine… it might not be fine.
  • ‘Best before’ and ‘use by’ dates have totally different meanings.
  • Never thaw frozen food on the bench or at room temperature.
  • Don’t cut the mould off and eat the rest – it’s probably all contaminated!

Help us set the record straight once and for all: is the 5-second rule bogus?

The 5-second rule is indeed a myth. Bacteria can transfer to food instantly upon contact with contaminated surfaces, regardless of how quickly it’s picked up.

Factors like the type of surface, moisture level and type of food influence contamination rates.

It’s always safer to discard dropped food to avoid potential risks.

When it comes to food safety, guesswork is not the way to go. UQ Mythbusters is back at it again – this time we’re holding our nose and peeling back the wrapper on some classic furphies about what you should and shouldn’t do when preparing food in the kitchen.

You might be surprised by how many of these have you hoodwinked!

Mark Turner is a Professor of food microbiology at UQ and serves as a Deputy Head of the School of Agriculture and Food Sustainability. When we reached out to him with a list of ick-inducing food myths he said that these issues were “very close to my research – and my heart”.  Suffice it to say, he’s the man for the job.

Pop on the kitchen gloves and let’s get into it.

Key points:

  • The 5-second rule officially debunked – into the bin it goes!
  • Do not rinse the raw chicken – repeat, do NOT rinse the raw chicken.
  • If it smells fine and looks fine… it might not be fine.
  • ‘Best before’ and ‘use by’ dates have totally different meanings.
  • Never thaw frozen food on the bench or at room temperature.
  • Don’t cut the mould off and eat the rest – it’s probably all contaminated!

Help us set the record straight once and for all: is the 5-second rule bogus?

The 5-second rule is indeed a myth. Bacteria can transfer to food instantly upon contact with contaminated surfaces, regardless of how quickly it’s picked up.

Factors like the type of surface, moisture level and type of food influence contamination rates.

It’s always safer to discard dropped food to avoid potential risks.

What’s the number one myth you think needs to be busted when it comes to food safety?

One prevalent myth is that washing raw poultry removes bacteria and increases food safety. This practice can actually spread bacteria in kitchens through splashing, increasing the risk of cross-contamination onto hands, plates, utensils and surfaces.

It is important to handle raw chicken carefully and cook it thoroughly by verifying an internal temperature of 75°C in the thickest part near the centre with a thermometer. This is the only effective way to kill harmful bacteria like Salmonella and Campylobacter.

By the way, every home should have a probe thermometer in the kitchen!

True or false: if it looks fine and smells fine, it probably is fine?

This is false and potentially dangerous. Many harmful bacteria and pathogens, such as Salmonella, Listeriaand E. coli do not affect the taste, smell or appearance of food.

Always follow storage and cooking guidelines and never rely on your senses to judge the safety of food. If in doubt, throw it out.

Is it ok to thaw frozen food at room temperature?

No, thawing food at room temperature allows time for bacteria to grow rapidly, especially on the surface which will be warmer.

Thaw food safely in the refrigerator or using a microwave.

Are plastic chopping boards more hygienic than wooden ones?

Both plastic and wooden boards can harbour bacteria if not cleaned properly. The key is to regularly clean and sanitise all chopping boards.

Replace them as soon as they become heavily scratched, cracked, or split, as these areas can harbour bacteria and are difficult to clean effectively.

A microscopic close up of bacteria

Image: Adobe Stock/LASZLO

Image: Adobe Stock/LASZLO

A microscopic close up of bacteria

Image: Adobe Stock/Giovanni Cancemi

Image: Adobe Stock/Giovanni Cancemi

A microscopic close up of bacteria

Image: Adobe Stock/Corona Borealis

Image: Adobe Stock/Corona Borealis

A microscopic close up of bacteria

Image: Adobe Stock/Surrender

Image: Adobe Stock/Surrender

What’s the number one myth you think needs to be busted when it comes to food safety?

One prevalent myth is that washing raw poultry removes bacteria and increases food safety. This practice can actually spread bacteria in kitchens through splashing, increasing the risk of cross-contamination onto hands, plates, utensils and surfaces.

It is important to handle raw chicken carefully and cook it thoroughly by verifying an internal temperature of 75°C in the thickest part near the centre with a thermometer. This is the only effective way to kill harmful bacteria like Salmonella and Campylobacter.

By the way, every home should have a probe thermometer in the kitchen!

True or false: if it looks fine and smells fine, it probably is fine?

This is false and potentially dangerous. Many harmful bacteria and pathogens, such as Salmonella, Listeriaand E. coli do not affect the taste, smell or appearance of food.

Always follow storage and cooking guidelines and never rely on your senses to judge the safety of food. If in doubt, throw it out.

Is it ok to thaw frozen food at room temperature?

No, thawing food at room temperature allows time for bacteria to grow rapidly, especially on the surface which will be warmer.

Thaw food safely in the refrigerator or using a microwave.

Are plastic chopping boards more hygienic than wooden ones?

Both plastic and wooden boards can harbour bacteria if not cleaned properly. The key is to regularly clean and sanitise all chopping boards.

Replace them as soon as they become heavily scratched, cracked, or split, as these areas can harbour bacteria and are difficult to clean effectively.

A microscopic close up of bacteria

Image: Adobe Stock/LASZLO

Image: Adobe Stock/LASZLO

A microscopic close up of bacteria

Image: Adobe Stock/Corona Borealis

Image: Adobe Stock/Corona Borealis

Why do some food products have a ‘best before’ date and some a ‘use by’? Is there any difference?

Yes, there is an important difference!

‘Use by’ dates indicate when a product is no longer safe to consume, and it should be discarded past this date.

‘Best before’ dates suggest when the product may lose quality (e.g. become stale) but remain safe to eat if stored properly.

Always follow ‘use by’ dates for safety-critical products like meat, dairy and seafood.

True or false: if you cut the mould off, the rest is ok to eat.

False. Mould on food can be spread much further than the visible spots seen on the surfaces of food. Many moulds also produce harmful mycotoxins that may diffuse across food.

It’s better to discard food if it has a visible mould spot, as it is likely that other parts of the food that look ok will also have low levels of mould (and possibly mycotoxins).

A close up image of a milk carton with an expiration date of 23 October

Image: Adobe Stock/runrun2

Image: Adobe Stock/runrun2

A close up image of cheese with mould growing on it

Image: Adore Stock/russell102

Image: Adore Stock/russell102

Why do some food products have a ‘best before’ date and some a ‘use by’? Is there any difference?

Yes, there is an important difference!

‘Use by’ dates indicate when a product is no longer safe to consume, and it should be discarded past this date.

‘Best before’ dates suggest when the product may lose quality (e.g. become stale) but remain safe to eat if stored properly.

Always follow ‘use by’ dates for safety-critical products like meat, dairy and seafood.

A close up image of a milk carton with an expiration date of 23 October

Image: Adobe Stock/runrun2

Image: Adobe Stock/runrun2

True or false: if you cut the mould off, the rest is ok to eat.

False. Mould on food can be spread much further than the visible spots seen on the surfaces of food. Many moulds also produce harmful mycotoxins that may diffuse across food.

It’s better to discard food if it has a visible mould spot, as it is likely that other parts of the food that look ok will also have low levels of mould (and possibly mycotoxins).

A close up image of cheese with mould growing on it

Image: Adore Stock/russell102

Image: Adore Stock/russell102

We hope you’ve been set straight by a few of these answers. Our thanks to Professor Turner for sharing his expertise – time to clear out the fridge and invest in that probe thermometer!

Have you got a myth in mind that could use some expert attention? Recently been on the receiving end of some received wisdom that seems a bit suss?

Submit your idea now for the next UQ Mythbusters!