If you love chips, you're probably familiar with the disappointment that comes with opening a bag and seeing that it's far from full.
And while some believe they are partially filled because companies are trying to pull a fast one on you to maximize profits, there's actually a legitimate justification for having extra air in the bag.
The empty space is intentional and helps protect the chips during its journey from the production plant to the store and then your home. This ensures that customers get as many full chips as possible and not a bag of crumbs, according to Joe Schwarcz, a chemistry professor at McGill University.
"These poor potato chips go through a rough travel schedule as they make their way from the producing facility to the store," Schwarcz said. "They are jostled about and we don't want to end up with a bag full of powdered potato chips."
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What's more, Schwarcz says it's actually not oxygen inside your chip bag.
"There is actually a reason why the bag looks the way that it does and why as soon as you open it, you hear as the air comes out. Well, it isn't actually air. It's pure nitrogen," Schwarcz said.
According to Fred Caporaso, professor of food science at Chapman University, companies choose nitrogen to fill their snack bags because the gas is inert, meaning it doesn't react with anything else, whereas the oxygen that it's in the air will react with the oil in the chips, thus causing them to go rancid quickly.
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This is why unopened bags of chips are still fresh two to three months later, thanks to nitrogen, Caporaso added.
Ok, but now, why do companies put so much nitrogen in the bags?
According to Caporaso, companies do this to avoid crushing any chips in the bag-sealing process.
"You don't want to have any chips to sit in the seal, which wouldn't seal correctly," Caporaso said. "So you have what we call 'head space', which is space where there's no chip, but there's air in there."
And don't worry, you're not paying for it either. Chips are sold by weight and federal law requires manufactures to disclose the weight of the actual contents in order to "prevent unfair or deceptive packaging and labeling, according to the Fair Packaging and Labeling Act of 1967.
"If you look at the weight on the bag and you can get yourself a scale and weigh it, you'll see that the chips weigh exactly what it says on the bag," Schwarcz said. "There are a lot of food scams out there, but this is not one of them," he concluded.