Regardless of where you drink, all too often it seems that a salty snack accompanies your beer. Many people think that bars serve peanuts, popcorn, and other sodium-heavy finger food because the salt causes you to drink more, improving bar profits. While bars may do this intentionally, there’s more to the story than initially meets the tongue. As it turns out, a salty snack with an IPA can actually reduce some of the bitterness.
Welcome back to high school chemistry. Salt, scientifically known as sodium chloride, is a small neutral molecule. But in the presence of water, sodium chloride can split into its respective ions: sodium (positively charged) and chloride (negatively charged). Now, taste buds are similar to air travel: you can only get past TSA with a specific ticket. Except that in our metaphor, instead of leading to your gate, airport security leads from the tongue to the brain through what’s known as a “selective ion channel.” The tongue actually has many selective ion channels for salt. When you eat salty food, the selective ion channels for sodium on your tongue send a signal to your brain that it interprets as salty.
Welcome back to high school chemistry.
Now let’s bring in the beer. In an IPA, the bitterness often comes from the hops, specifically the hops’ alpha acids (known to science nerds as humolones). While eating salty peanuts, ion channels attract and funnel sodium ions through the tongue. But for alpha acids, the tongue recognizes them using surface receptors, which attract specific (in this case bitter) molecules based on their charge and size. All surface receptors on the tongue require the molecule that it attracts to fit perfectly or else a signal to the brain won’t be sent.
If you’re still with me, here’s where it gets interesting. As it turns out, salt molecules are small enough that they can accidentally fit into part of a bitter surface receptor. Think about the children’s toy that requires a kid to match the circle block into the circle hole and the star block into the star hole. Now imagine putting a small star block into the circle hole and then trying to fit the circle block into that hole as well. Obviously, it isn’t possible. This same principle holds for a sodium molecule: when you eat salty food, the sodium ions block the bitter alpha acids from binding to surface receptors on the tongue and sending a signal to the brain.
When you eat salty food, the sodium ions block the bitter alpha acids from binding to surface receptors on the tongue and sending a signal to the brain.
Want to test the theory? Next time you’re at the bar, order up your favorite IPA and a bowl of salted nuts or popcorn. First take a sip of beer and taste all of the flavors — recognize the bitterness from the hops. Then eat some peanuts or popcorn and keep eating them until your mouth becomes salty enough that it begins to water. Now, take another sip of beer. More muted right?
For all of those beer lovers who tend to stay away from IPAs, be bold! But when the bitterness becomes too much, make sure you have a salty snack on hand.