How To Keep Potato Chips Fresher Longer: A Scientific Inquiry
Stale potato chips are flaccid discs of sadness. They are annoying like a fruit fly in a freshly cleaned kitchen, or a lip-smacking patron in a quiet sandwich shop: not annoying enough to push you to a breaking point, but just enough to get under your skin.
Unlike long grain white rice or honey, a bag of chips has a pretty short life span. Based on decades of experience, I've concluded that, if left unsealed, an open bag of chips loses freshness in fewer than 36 hours. Varying levels of sealedness will allow you to eke out a few extra days, but even the best tactics or equipment won't yield more than a week.
Sure, you could put them in a Tupperware container or break out the FoodSaver, but let's be realistic: the chips are going to get stored in their bag of origin.
When I seal a bag of chips, I want something easy and cheap, ideally with no investment of time, money, or thought. I need a method I can turn to in a jiffy, because usually I am closing a bag hastily while simultaneously peeling my 2-year-old away from a chandelier.
I tested several methods of chip-bag sealing to determine how long each would preserve the chips inside. I did not use pure science: no moisture readers or fancy instruments were used in my experiments. Instead, each day, I checked to see whether the chips reached a "too stale to eat" point. Additionally, I considered the price point and the pros and cons of each method.
Crumple the top of the bag or just leave it open
This requires no thought, but it's the least effective in keeping the bag sealed. The chips get stale quickly. There's nothing to hold the edge of the bag in place, so it naturally (and noisily) uncoils. With a good tight crumple I got at most 48 hours using this method. Leaving it open is slightly better than just leaving an open bowl on the table.
Both these methods drive me bonkers. You might as well just throw the bag away if you're not going to seal it at all. When I see this method employed by other members of my household, I passive-aggressively remedy this with a better seal, using any of the below methods:
The foldover
In this method, you tuck the open end of the bag under weight of the remaining chips. Set the bag of chips sideways so that the weight of the remaining chips holds the bag in place. This foldover buys you another 24 hours, extending the life of your chips to about three days.
This requires as little forethought as the crumple. It requires no object or clip to keep the open end closed, although you might not be able to tuck as tightly if there are too many chips in the bag. One method to combat this: bookend a heavier item (like a four-pack of cornbread mix from Costco) against the folded edge.
The origami pocket fold
As documented here and here, this method uses origami to create a self-closing pocket. This is perhaps the most effective of the free closing methods. The only investment is the time to learn the technique. It does a better job of keeping the chips from falling out than the crumple or the foldover, and it keeps the chips fresher. The effort required for this got me about five days.
The downside: it requires learning a new skill! It took me a few tries to do it successfully. And I don't know if I can deploy the muscle memory to do this quickly. My subconscious will deviate toward a clip or the foldover.
Office supplies
All prices based on Amazon.com listings
A rubber band (cost: $5.49 for 1/2 pound, probably $.01 for a single rubber band)
The rubber band is best used with the crumple or the fold over. Depending on the tightness of your crumple or fold-over, it's effective in prolonging freshness and can give you about the same amount of time as the origami pocket fold (five days).
Size matters with the rubber band. You need something that could hold a Sunday newspaper (from 20 years ago). Too small and you risk snapping the band. Too big and the band won't fit snugly around the bag.
A binder clip (cost: $5 for 12, so about $.42 apiece)
This is essentially a chip clip, with less of a surface area. The binder clip prolongs freshness better than just the crumple or the fold over, and offers comparable performance to the rubber band and the origami seal.
Effectiveness varies with the size of the binder clip. You need, at minimum, a medium-sized clip for peak effectiveness (enough to hold a short screenplay). In the past I have tried smaller sizes, and they just slide off the top of the bag. Extra large is preferable, if you can smuggle one from your office.
Tape (cost: $7.08 for 180 yards of 2-inch masking tape, so about $.01 for 8 inches of tape)
Tape augments the foldover or crumple by holding the unsealed top to the side of the bag. Regardless of whether it's masking, cellophane, or painter's tape, tape loses stickiness too quickly due to the oil (or, to be honest, potato chip grease) on your fingers. Skip tape.
OXO Good Grips Bag Clips ($5.99 for 2)
The chip clip works better than the crumple or the fold alone. It offers a larger surface area than the binder clip or rubber band. Plus it frees up office supplies for their intended use. Chips will last six to seven days days with a chip clip.
I recommend one—and only one—clip: the Oxo Good Grips Bag Clips, long version, due to the level of craftsmanship. The spring coil wraps around both sides of the clip, and the rubber lips provide a tighter seal than the plastic teeth on lesser quality chip clips.
Every other chip clip is a roll of the dice, and I cannot confidently recommend any of them. I've probably gone through and broken dozens of chip clips in my life, in every size. An aggressive squeeze or a fall to the floor has been enough to shatter many clips. And if you receive a free chip clip at an event like a town fair, dispose of it immediately.
Conclusion
If you're dead set on investing in chip freshness, your best option is the OXO chip clip. Short of that, I would recommend a medium-to-large binder clip. If you're cheap like I am, I recommend the foldover. The most fun and gluttonous route, though, is to just shine off the bag in one sitting, avoiding stale chips altogether.