This Type of Coffee Is Least Likely To Stain Your Teeth
For all the good coffee does, it’s not easy on our teeth. The components in our favorite morning beverage can discolor our pearly whites with every sip. However, not all coffees stain equally. And it turns out that one type of coffee will induce far less teeth discoloration than the rest. Based on how they’re roasted, some coffees are more prone to tinting our teeth than others. While it might seem counterintuitive, light-roast coffees are, in fact, the worst offenders when it comes to staining our teeth.
BREAKING DOWN THE COFFEE ACIDITY
On the pH scale, which measures a substance’s acidity, coffee tends to sit on the acidic end. (For reference, water is completely neutral at 7 on the 0 to 14 scale.) Coffee has a pH between 4.9 and 6.2, according to Monica Bebawy, a dentist at the New York University College of Dentistry.
Your teeth are vulnerable to acidic compounds. “Enamel is a super hard substance, but actually porous,” Bebawy tells Inverse. If you enjoy a food or drink with a pH of 5.5 or lower, the enamel starts to break down, allowing the food’s natural pigments to make more persistent stains.
Tannins and chlorogenic acid are the two polyphenols, or naturally occurring plant compounds, that are responsible for staining our teeth, Bebawy says. Also found in wine and chocolate, tannins impart the drink’s pleasantly bitter flavor. Tannins and chlorogenic acid adhere to our teeth even after they’re washed away, resulting in the underlying pigment.
When coffee is roasted, the bean’s tannins and chlorogenic acid break down. Roasting the coffee longer actually increases its pH. However, they’re left more intact in light-roast coffee, which isn’t roasted for as long as dark-roast coffee. Light-roast coffee, then, has a lower, more acidic pH than dark-roast coffee, which means it can do greater damage to your chompers.
TIMING IS EVERYTHING
The time it takes for you to consume your coffee also impacts pH. Saliva has an average resting pH of 6.7, and the mouth’s resting pH doesn’t dip below 6.3. Drinking coffee temporarily changes your mouth’s pH. If you drink your daily coffee in half an hour, that change doesn’t last very long. But if you take two hours to drink a single cup of coffee, “you’re presenting your teeth in your mouth with constant attack of acid,” Bebawy says. You’re not giving your saliva a chance to act as a buffer and reestablish pH levels. “So you can drink as much coffee as you want in a short amount of time to be more protected.”