Sweet tea is mildly acidic. Commercial sweet teas typically have a pH between 3.76 and 5.18, placing them below the neutral mark of 7.0 but well above the acidity of sodas, fruit juices, and most other popular beverages. The exact pH depends on the brand, how it’s brewed, and what else is added.
How Acidic Sweet Tea Actually Is
A study published in the Journal of the American Dental Association measured the pH of hundreds of commercial beverages available in the U.S. Among the sweet teas tested, pH values ranged from 3.76 (Admiral Iced Tea Sweet Tea) to 5.18 (Milo’s No Calorie Famous Sweet Tea). Milo’s regular Famous Sweet Tea landed at 4.66, and Red Diamond Fresh Brewed Sweet Tea came in at 5.04.
For context, pure water is neutral at 7.0, and anything below that is acidic. So yes, sweet tea falls on the acidic side. But the range is wide enough that some sweet teas are only slightly acidic while others are noticeably more so. Across all 17 teas tested in that study (sweet and unsweetened), the average pH was 3.48, meaning sweet tea brands actually tended to be less acidic than many other tea products.
Sweet Tea Compared to Other Drinks
Sweet tea is far less acidic than most of what people drink throughout the day. Coca-Cola Classic has a pH of 2.37, Pepsi sits at 2.39, and lemon juice comes in at 2.25. Those drinks are tens to hundreds of times more acidic than a typical sweet tea, because the pH scale is logarithmic: each whole number represents a tenfold difference in acidity.
Coffee, often considered a classic acid-reflux trigger, measured at 5.11 in the same study, which is right in the middle of the sweet tea range. Bottled water (Aquafina) came in at 6.11, and municipal tap water tested at 7.20. So sweet tea slots in between soda and water, roughly comparable to coffee in most cases.
What Makes Sweet Tea Acidic
The acidity in sweet tea comes primarily from compounds in the tea leaves themselves. Black tea contains tannins and other naturally occurring organic acids that lower the pH of the brew. Sugar, on its own, doesn’t meaningfully change the acidity of a liquid. Adding sugar to tea makes it sweeter but doesn’t push the pH up or down in any significant way.
Your brewing water plays a bigger role than sugar does. Research published in Food Chemistry found that the pH of brewing water, which can range from about 5.6 to 7.4 depending on the source, directly influences the final acidity of the tea. Water with a lower pH (more acidic to begin with) produces a more acidic cup. Water with higher mineral content and a more neutral pH tends to yield tea that’s slightly less acidic. Brewing time and tea concentration also matter: the longer the steep and the more tea leaves used, the more tannins dissolve into the water, pulling the pH down.
Sweet Tea and Your Teeth
Tooth enamel begins to dissolve at a pH of about 5.5. The deeper mineral layer of teeth, called dentin, is even more vulnerable, with a critical threshold around 6.8. Some sweet teas fall right around or below the 5.5 mark, which means they can contribute to enamel erosion over time, especially with frequent sipping throughout the day.
The sugar in sweet tea creates a second problem. Bacteria that live naturally in your mouth, particularly one species called Streptococcus mutans, feed on sugar and produce lactic acid as a byproduct. Lab studies show these bacteria can drop the pH in their immediate environment from around 7 down to 4 over the course of four hours when sugar is available. So even if the tea itself is only mildly acidic, the sugar fuels additional acid production directly on the surface of your teeth. The combination of the tea’s own acidity and the bacterial acid from sugar is what makes sweet tea harder on enamel than unsweetened tea or plain water.
Sweet Tea and Acid Reflux
If you deal with heartburn or gastroesophageal reflux, sweet tea may be worth watching. A study examining the effect of tea and coffee on the valve between the esophagus and stomach found that caffeinated tea significantly reduced the pressure that keeps that valve closed. When that pressure drops, stomach acid is more likely to splash upward into the esophagus. In the study, tea actually produced more reflux episodes than coffee with the same caffeine content. Decaffeinated coffee, by contrast, did not weaken the valve.
The caffeine in black tea is the main driver here, not the sugar or the tea’s own mild acidity. A standard cup of brewed black tea contains roughly 40 to 70 milligrams of caffeine, but a large glass of sweet tea brewed strong can push well above that. If reflux is a recurring issue for you, the volume matters: people tend to drink sweet tea in much larger servings than hot tea or coffee, which increases both the caffeine load and the total liquid sitting in the stomach.
How to Reduce the Acidity
A few simple adjustments can bring down the acidity of homemade sweet tea. Using filtered tap water or spring water with a more neutral pH (closer to 7) rather than distilled or purified water gives you a less acidic starting point. Shortening the steeping time reduces the amount of tannins extracted from the leaves. Cold-brewing tea overnight instead of using boiling water also tends to produce a smoother, less acidic result because heat accelerates the release of acidic compounds.
Drinking sweet tea with a meal rather than on its own helps as well. Food buffers the acid in your mouth and stimulates saliva production, which naturally neutralizes acidity and rinses sugar off your teeth. If you’re sipping sweet tea throughout the afternoon, rinsing with plain water between glasses is one of the simplest ways to limit its effects on both your teeth and your digestive comfort.