How much air is in YOUR favourite bag of crisps? MailOnline reveals how popular packets compare - including those that are 37% EMPTY (and how to get more snack for your money)

• e-mail

Whether it's a tangy Dorito or a crunchy NikNak, crisps are officially one of the UK's favourite snacks. 

When cracking open a packet, there's nothing more annoying than being met with a whoosh of air and a disappointing pile of crumbs. 

The gas inside the packets is nitrogen, which helps to keep your crisps crunchy and stops them from going off too quickly. 

But which brands have the worst air-to-crisp ratio? 

To find out, MailOnline carried out its own experiment, with shocking results. So how does your favourite stack up? 

How does your favourite stack up? MailOnline reveals how much air is in popular crisp packets 

MailOnline carried out its own experiment, with shocking results. So how does your favourite stack up?

For the experiment, we tested the amount of air in packets of five of the nation's favourite crisps - Pickled Onion Monster Munch, Tangy Cheese Doritos, BBQ Beef Hula Hoops, Walkers Cheese and Onion, and Wotsits. 

These were all purchased for £1 from Tesco Express.  

To find out the volume of these sealed packets - crisps and air still included - we filled a jug with 1,150ml of water, before plunging the packets in one-by-one. 

Once these initial measurements had been noted down, we decanted the crisps into empty vacuum packets (somehow resisting the urge to eat any in the process), before using a vacuum machine to suck out all the air and reseal the packet. 

At this stage, our crisps were looking very squished and sad, but we carried on, placing the packets back into the water, which allowed us to see the volume without air. 

With a bit of quick maths, we could then work out the percentage of air in each crisp packet. 

When cracking open a packet, there's nothing more annoying than being met with a whoosh of air and a disappointing pile of crumbs

READ MORE: The science behind the perfect crisp sandwich

In the study, the team assessed 10 pairings of Walkers crisps with Subway sandwiches. Their analysis focused on three key features of the pairings – flavour, aroma and texture

Advertisement

The results revealed that the BBQ Beef Hula-Hoops had the least air in their packet, with just 20 per cent of the bag taken up by gas. 

This was followed by Wotsits (24 per cent), and Pickled Onion Monster Munch (26 per cent). 

In contrast, Walkers Cheese & Onion were found to contain the most air (37 per cent), followed by Tangy Cheese Doritos (33 per cent). 

Before you feel shafted, there's an important caveat to note. 

PepsiCo UK, the maker of four of the five crisps tested (except Hula Hoops), explained to MailOnline that it fills its packets by weight rather than volume. 

It also uses state of the art technology to ensure the right amount of crisps are in each pack. 

'To keep our crisps fresh and crunchy, we blast a small amount of air into the pack just before we seal it,' a spokesperson said. 

'This also cushions and protects the crisps in the packet as they make the journey from our factories to retailers across the country, and eventually into people's homes.'

Our test comes shortly after scientists revealed the best crisps for crisp sandwiches. 

Dr Stuart Farrimond, a food scientist, reviewed the flavour compounds in popular sandwiches and crisps, in a study held at the University of Chester and commissioned by Subway and Walkers.

His findings suggest that the sweet, sour and umami flavours in a Chicken Tikka sandwich are perfectly enhanced by the salty seasoning in Ready Salted crisps.

Dr Farrimond said: 'Sandwiches are a much-loved lunchtime staple, but flavour-pairing theory and consumer testing has allowed us to explore news ways that we can elevate this familiar meal and boost both texture and flavour.' 

Chocolate side up or down? Scientist reveals the best way to eat a Chocolate Digestive 

With their crunchy biscuit base and luxurious chocolate topping, Chocolate Digestives have been favourites among biscuit lovers since they launched back in 1925.

But one question has been heavily debated about the biscuits – which way up should they be eaten?

Now, researchers from Oxford University believe they have settled the debate, and claim that you should pick up the biscuits with the chocolate side up, but flip them over before eating them.

The experts say this method allows the brain to register the chocolate coating, while flipping them before eating maximises the 'oral-somatosensory experience' of the chocolate melting on the tongue.

Read more here 

Researchers from Oxford University believe they have settled the debate, and claim that you should pick up the biscuits with the chocolate side up, but flip them over before eating them