Why Does Cinnamon Taste Hot? And Why Does Mint Taste Cold?

Science is a process that helps us answer questions about how the world works. Why does cinnamon taste hot? Why does mint taste cold? Why does soda fizz more when you put ice in the glass? Readers contacted us with these questions, and we have answers.

Why do carbonated beverages fizz more when you add ice?

The short answer is because ice has a rough surface. The long answer is more complicated.

Carbonated beverages have carbon dioxide dissolved into the liquid. Under pressure, more carbon dioxide can be dissolved into the liquid than is possible at regular atmospheric pressure. When that pressure is released – like when you pop the top on a can of soda – the liquid can’t contain as much carbon dioxide, so some of the dissolved carbon dioxide begins forming tiny bubbles of gas. Because these gas bubbles are less dense than the surrounding liquid, they begin rising toward the surface. This is why you get a lot of bubbles when you first open a soda or pop the cork on a bottle of champagne.

“If there is a solid place where these tiny bubbles can collect – such as the rough spots along the side of an ice cube – the tiny bubbles merge into larger ones,” says Gabriel Keith Harris, a professor of food science at NC State. “That process is called nucleation.”

You see this in champagne glasses, where tiny flaws along the side of the glass serve as nucleation sites and create a steady stream of bubbles rising to the surface. The same thing happens in a soda when you put ice into it, because the ice introduces a lot of nucleation sites all at once.

Why does mint taste cool? And why does cinnamon taste hot?

“In order to answer those questions, we have to talk about several receptors that are found in nerve endings,” Harris says.

“One of these receptors is called TRPV1, and it is sensitive to a specific range of chemicals – such as cinnamaldehyde (which is found in cinnamon) and capsaicin (which is found in jalapeños and other peppers). When TRPV1 encounters increasing levels of those chemicals, it registers as a warm to hot sensation, even though there’s no change in temperature.”

That’s why cinnamon tastes hot – the cinnamaldehyde in cinnamon is triggering our TRPV1 receptors.

“The rapid change in pH that occurs as carbonated beverages release their carbon dioxide bubbles activates another receptor, called TRPA1, in a way that registers as a stinging sensation – so there’s actually some overlap between the last question and this one,” Harris says.

TRPV1 also helps explain why mint tastes cool. That’s because there are chemicals in mint that do two things.

“First, mint inhibits the activation of TRPV1 – so our nerve receptors are triggering fewer warm sensations,” Harris says. “Second, mint activates a receptor called TRPM, which creates a cool sensation. It’s a double whammy.”

In other words, mint tastes cool and cinnamon tastes hot because of the chemicals found in those two foods and how our body responds to those chemicals.