Sometimes we eat with our ears.
So say the food scientists. They contend that crispy and crunchy are two different sensations. One we sense with our mouths and the other with our ears.
Naturally, they looked to the ultimate crispy and crunchy food: the potato chip.
It’s just potato, hot fat, and salt, but together they make sensory magic. When we eat potato chips we hear the crunch, but we’re really sensing it in our mouths. When it comes to their crispness, even though it’s bound up with the crunch, we’re assessing it with our ears.
Pringles. The favorite chip of the scientific community.
Researchers love the unnatural uniformity of Pringles with their low level variances. It’s what made them an ideal test material for a team of Oxford University scientists who designed a chip mastication study to confirm the link between sound sensation and taste perception. Chip-eating test subjects were outfitted with microphones and headphones to capture and deliver the sounds. When the sound level was amplified, the potato chips were perceived as both crisper and fresher. Fresh or stale, crunchy or soggy, the subjects happily chomped away, as long as the auditory cues continued to suggest freshness.
In the first study the test subjects enjoyed stale chips that sounded fresh; in a second study they rejected fresh chips when they didn’t hear the crispness. This time the Oxford chip-eaters ate Pringles while wearing sound-blocking headphones. Without an auditory cue they quickly lost interest in the Pringles no matter how fresh and crunchy they tasted.
Crunching the numbers.
Potato chips are a $6 billion business in the U.S. That big chip business means that serious research dollars flow to the community of food scientists in the quest for the perfect crunch. Engineers employ signal analyzers to measure the sound frequencies of airborne crunches (the chew you can hear from across the room) and artificial mouths(?!) to gauge the mechanics of something they call oral residence—the combination of teeth time and tongue compressions. They regulate chewing with metronomes to perform frequency-time studies of mastication, and study chip eating among different ethnic groups to determine if there is a genetic or cultural component to the range of crispy/crunchy sensory perceptions.
It’s all about that first chip out of the bag.
Pristinely crisp with a crunch that is unsullied by time or ambient humidity, it’s clearly both a gustatory and an auditory pleasure. With all the chip analysis and quantification of sensory inputs, we can only hope that the snack industry can crack the code, and someday every potato chip will be as satisfying as the first one out of the bag.