The air in local chip bags

Trending on Business Insider SA is an article on the quantity of air found in local chip brand packets – but which also uncovers the why behind this. Consumer deception is not in play here…

Large potato chip bags in South Africa are sometimes only filled two-thirds with chips. The rest of the bag consists of air – mostly nitrogen – which amounts to between 14% and 37% of the volume of bags tested. Across all bags tested, the average chip packet was 27% air.

Business Insider SA measured the percentage volume of air versus chips in seven different types of potato chips available on local shelves. We did this using a large beaker, a ruler, and a vacuum sealer.

By measuring water displaced in the beaker when unopened, and once again when opened and vacuum sealed to remove all excess air, Business Insider was able to find a percentage difference that – although not exact – gives a good idea of how much air you’re buying in a standard large bag of chips.

The testing covered large bags of Simba, Lays, Doritos, NikNaks, Flanagan’s, and Pringles, as well as private-label chips from Woolworths and Pick n Pay. 

Apart from Pringles, which is made by Kelloggs, most mainstream chip brands in South Africa are manufactured and packaged by just two primary companies – AVI and PepsiCo – and yet have significant discrepancies between brands within the same portfolios.

We found that large bags of NikNaks had the least amount of nitrogen in the bag, at 14%. Lays, Flanagan’s, Woolworths private label chips, Pringles, and Doritos all had similar levels in their packets – ranging between 23% and 27%.

The outliers at the higher end of the scale were Simba and Pick n Pay private label chips, which resembles Simba chips. These bags were 33% and 37% air, respectively.

All bags were, however, roughly equal in dimensions and had approximately the same net weight of chips inside.

Not a rip off

Although it may feel like chip makers are ripping you off when a bag is up to 37% air, this isn’t necessarily the case. Manufacturers use what they call “slack fill” to protect products, and as long as it’s not misleading, they’re free to do so. 

South African National Standard (SANS) oversees food packaging and labelling in South Africa and dictates that manufacturers fill packages so that shoppers won’t “reasonably be misled with respect to the quantity or identity of the product it contains”.

If consumers can’t see the product through the packaging, as is the case with most chip bags, SANS says the slack fill must be “functional”.

In the case of chip packaging, this nitrogen gas mix used to inflate bags is functional, says Gawie Roodt, director at Africa Industrial Engineering Services.

“The inflated nitrogen bag limits bacterial growth and protects the chips from breaking into fine pieces during the packaging and handling process – in the factory, in transit, and on supermarket shelves,” says Roodt.

In cases where this slack fill is misleading, consumers may have some recourse under the Consumer Protection Act, which states that companies can’t falsely represent goods or services – but proving where to draw this line in a bag of chips may be difficult.

How chip manufacturers determine the chip-to-air ratio

Craig Weitz, senior director of R&D at PepsiCo SSA, which makes Doritos, Simba, Lays, and NikNaks in South Africa, says chip makers work to find the perfect balance of chips and air in each bag to find “an optimum fill level”.

Puffy chip packets may look great on shelves and lure more consumers, but they’re also more expensive to transport and take up more shelf space. They’re also likely to annoy more shoppers. 

For these reasons, Weitz says the decision about how much nitrogen to use focuses on delivering the best consumer experience across quality, cost, and sustainability.

“We run trials for new products to determine the absolute highest fill level to run without compromising quality and efficiency”, Weitz said. “A general target is around 75-80% fill level at the bag maker. However, this can vary based on product and even seasonality of raw materials”.

Despite the tight control over these targets at a factory level, Weitz says some air discrepancies may occur due to changes in altitude between packing and sale locations and settling over time – both of which may explain variations in Business Insider’s findings.

Using nitrogen in chip packets

Weitz says a nitrogen gas mix, squirted into the bag before sealing, is the industry standard for potato chip preservation. The FDA says this gas is safe provided its “used in food at levels not to exceed current good manufacturing practice”.

Weitz says PepsiCo uses nitrogen “to displace oxygen to prolong the quality of products by reducing oil oxidation or rancidity of flavours in the product”.

Nitrogen gas is an excellent food preserver because it’s tasteless, odourless, and harmless. Unlike oxygen, nitrogen doesn’t react with molecules around it, keeping chips crispy and extending their shelf life.

Net weight is the best value guide

Although marketing, profit, and on-shelf presentation may play some role in how much air you find in a bag of chips, it’s not the best representation of value. The packet of NikNaks, for example, had the least amount of air – yet the chips did not reach the 86% mark of the bag. Instead, they settled somewhere around the 30% mark.

If you’re concerned about getting your money’s worth, therefore, the bag’s net weight is the best indication.

Under South Africa’s Trade Metrology Act of 1963, manufacturers must include the net weight of a product in its labelling – and this, not how much air is in your puffy packet, is the best indication of how many chips you’re actually getting.

Source: BusinessInsider SA