Forward by Jennifer Rae Vliet: Let’s have one last hurrah before we welcome the cooler weather and learn a little bit about a very special creation of God’s…the mint plant.
By Paul Adams
How chemistry tricks us into feeling like we’ve downed ice cream or a frosty drink.
Bite into a fresh mint leaf and, in addition to the minty flavor, there’s a distinct cooling effect, like chilly water on your tongue. Mint-flavored gum and candies, even more so. How does that work?
Why Mint Makes Our Mouths Feel Cold
Mint works just like chile peppers do, tricking us into thinking we’ve eaten something hot or cold.
When you put a chile in your mouth, the compound capsaicin, which abounds in peppers, triggers particular receptors on your tongue. Known as TRPV1, these receptors are responsible for signalling when we’ve eaten something physically hot, like the first sip of tea.
But the shape of the capsaicin molecule allows it to activate the receptors, sending a “hot” message to our brains even though the stimulus is just chemical, not physical like heat. This phenomenon is known as chemesthesis.
Mint plants such as peppermint (Mentha piperita) produce menthol, a terpene compound with characteristic mint flavor. But, just as capsaicin activates TRPV1, menthol activates a neural receptor called TRPM8, which is primarily responsible for detecting cold temperatures. Menthol fools our tongues into sending a message to our brains saying “That’s icy cold!”
Why Mint Gum Makes Our Mouths Feel Especially Cold
Mint gum sometimes uses menthol for its cooling effect; or sometimes derivatives of menthol that pack a stronger cooling punch. Many such synthetic compounds were developed by the skin-care industry, to give a refreshing cool sensation to shaving creams and shampoos. (The most powerfully minty compound, icilin, is about 200 times more cool and refreshing than menthol. As far as I know, it’s not used in any commercial products.)
Some gums and candies also add sugar derivatives known as sugar alcohols. These are low-calorie, low-glycemic-index sweeteners—but some of them, such as xylitol and erythritol, have a bonus effect. When they dissolve in the mouth, they absorb a significant amount of heat, producing a cooling sensation. Unlike menthol, though, the process of sugar alcohol crystals dissolving in water literally lowers the temperature of your mouth. Pretty cool!
Mint-Cookie No-Churn Ice Cream
Why This Recipe Works
An ice cream maker works by churning a mixture (usually milk, cream, sugar, and egg yolks) as it freezes to inhibit the formation of ice crystals and to incorporate air—so that instead of a solid block of frozen milk, you have silky, creamy ice cream. But we found an easy way to ditch the ice cream maker by whipping cream in a blender. The air in the whipped cream stood in for the air normally incorporated by churning. Using two liquid sweeteners—sweetened condensed milk and corn syrup—kept the ice cream soft and scoopable. We added crushed Oreo cookies and peppermint extract for a combination that was mint to be.
Gather Your Ingredients
2 cups heavy cream, chilled ♥ 1 cup sweetened condensed milk ♥ ¼ cup whole milk ♥ ¼ cup light corn syrup ♥ 2 tablespoons sugar ♥ ¾ teaspoon peppermint extract ♥ ¼ teaspoon table salt ♥ ⅛ teaspoon green food coloring ♥ 4 Oreo cookies, crushed coarse (½ cup)
Before You Begin
The cream mixture freezes more quickly in a loaf pan than in a taller, narrower container. If you don’t have a loaf pan, use an 8-inch square baking pan.
Instructions
- Process cream in blender until soft peaks form, 20 to 30 seconds. Scrape down sides of blender jar and continue to process until stiff peaks form, about 10 seconds longer. Using rubber spatula, stir in condensed milk, whole milk, corn syrup, sugar, peppermint extract, salt, and food coloring. Process until thoroughly combined, about 20 seconds, scraping down sides of blender jar as needed.
2. Pour cream mixture into 8½ by 4½- inch loaf pan. Gently stir in cookies. Press plastic wrap flush against surface of cream mixture. Freeze until firm, at least 6 hours. Serve.