Why Are Chip Bags Full of Air?

(Last Updated On: September 8, 2021)

You know the feeling. You open a bag of chips because you’re looking for a snack–maybe it’s your break and this is the only chance you’re going to get for a good while. Then you open the bag and find that it’s actually mostly just full of air, and there aren’t even that many chips inside to begin with. Not a great time. You might be thinking there’s a reason for chip bags to be like this–otherwise somebody would have sold a bag filled to the brim to knock out all the competition. So why are chip bags full of air? Maybe there actually isn’t air inside of those bags. 

Further Reading: What Is the Most Expensive Chip?

Is it even air?

Hate to break it to you, but that’s not air inside of your chip bag. We’re not being semantic with “oh there are actually chips in there,” as annoying as that would be. Most of the empty space in chip bags is nitrogen. While the air around us is over 75% nitrogen, the gas inside of your bag of oddly flavored potato chips is substantially different. Part of the manufacturer’s goal is to limit how much oxygen is in each bag. 

Why limit oxygen? Well chiefly, oxygen is known to oxidize things it comes into contact with, and this is one of the prime ways food goes bad. You probably knew this intuitively already. Most of us don’t just leave an open bag of chips lying around, people tend to clip or fold the bag. Otherwise they get really stale really quickly. Making the oxygen content of each chip bag as low as possible serves a functional purpose then; it keeps the food inside from going bad. A study in 1994 concluded that oxygen concentration had to be below 0.01 atmospheres in order for the chips to extend their shelf life substantially. That basically means the gas inside your chip bag has to be down to around 1% oxygen.

Slack Fill

Alright, so we know the stuff inside the bag technically serves a purpose. But why does the bag have to be so empty? Well for starters, we know they can’t just fill each bag to the absolute brim, or else it wouldn’t be able to close and seal properly. If the bag is too full, well the chips inside are going to jostle against each other and break. Then they’d just become dust and only fill up like a quarter of the bag again. Think about it this way, you can make a chip ground to dust fit into a smaller space than the original chip. Plus the vacuum sealed bags are normally inflated a bit like balloons; turning the bag into a kind of cushion.

So to keep from selling you just straight up chip dust, manufacturers leave some space in the packaging so their products have some shape when they make it to their buyers. The problem, of course, is that many chips don’t come in very convenient sizes. There’s a reason why Pringles have a better package-to-food ratio than say Doritos. The former is designed to stack on itself, while the latter is not. Until they start designing triangular tubes to sell your nacho cheese and cool ranch in. Kitchen Cabinet Kings found that a tube of Pringles is about 28% gas, while a bag of Doritos is normally 48% gas. Cheetos were an outlier, though–about 59% gas. Generally across manufacturers, the average was around 43%, so it’s not too far off the mark to say your bags are consistently only half full.

So the obvious question, why don’t manufacturers just design their products to be more efficient?

Well… You already knew the answer to that. 

The Fair Packaging and Labeling Act

Unsurprisingly, we’re not the only ones who are a bit salty at how few chips we’re getting per bag. That’s where the Fair Packaging and Labeling Act, which has actually been kicking around since 1966.

 In relation to your potato chips, it means there has to be a listed weight on the bag. The problem, of course, is that humans are really bad at judging weight. People will always associate more product with packaging that’s just larger–even if it’s lighter. So there’s still a vested interest in having packaging filled with nothing. There’s an entire subreddit dedicated to misleading packaging in this way.

So, at the end of the day, there’s actually a functional reason for your chips to come in less-than-full bags. Cheetos having packaging that’s almost 60% not-Cheetos is probably them trying to pull a fast one on you, though. 

Honestly a bag of autumn leaves might have less air than our next bag of convenience store chips. See if you can even tell the difference here.

About the Author:

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Kyler is a content writer at Sporcle living in Seattle, and is currently studying at the University of Washington School of Law. He's been writing for Sporcle since 2019; sometimes the blog is an excellent platform to answer random personal questions he has about the world. Most of his free time is spent drinking black coffee like water.