What soft drink has the least acid?

January 11, 2026 •

4 min read

According to a 2007 study published in General Dentistry, root beer was found to be the safest soft drink for teeth due to its low acidity. This surprising fact highlights how ingredients, like citric and phosphoric acids, determine a beverage's potential for enamel erosion.

Quick Summary

The least acidic soft drink is root beer, which typically has a pH of 4.0-4.7 and often lacks the stronger acids found in other sodas. This difference stems from its unique ingredient profile, which relies on flavorings rather than phosphoric or citric acid for its taste. Understanding beverage acidity is key for protecting dental enamel and managing acid reflux symptoms.

Key Points

Least Acidic Soft Drink: Root beer is generally the least acidic commercial soft drink, often having a pH range between 4.0 and 4.7.
Why Root Beer is Less Acidic: Its lower acidity is attributed to the fact that it does not typically contain phosphoric or citric acid, unlike most colas and fruit-flavored sodas.
Most Acidic Sodas: Colas and diet colas, which contain phosphoric acid, are among the most acidic sodas, with pH levels as low as 2.5.
Enamel Erosion Threshold: Tooth enamel starts to erode at a critical pH level of 5.5, meaning all soft drinks are potentially harmful to teeth over time.
Flavored Sparkling Water Acidity: The addition of fruit flavorings, often containing citric acid, can make flavored sparkling waters significantly more acidic than plain varieties.
Best Drinks for Dental Health: The healthiest beverage choices for dental health are plain water and milk, which help neutralize acids and strengthen enamel.

Root Beer: The Least Acidic Soft Drink

While the thought of soft drinks and low acidity might seem contradictory, one soda stands out for its relatively mild pH: root beer. Unlike colas and citrus-flavored sodas that rely heavily on strong acids like phosphoric and citric acid, most root beers achieve their flavor profile without these highly erosive ingredients. This significantly reduces the beverage's acidic content, making it a notably better option for dental health and for those with acid reflux concerns.

The Science Behind Root Beer's Lower Acidity

Soft drink acidity is determined by its pH level, a measure on a scale from 0 (most acidic) to 14 (most alkaline), with 7 being neutral. Any beverage with a pH below 7 is considered acidic, but a pH of 5.5 is the critical threshold at which tooth enamel begins to erode. While all sodas are acidic and fall below this threshold, root beer sits at the higher, or less acidic, end of the soft drink scale.

Several factors contribute to root beer's gentler nature:

Absence of Major Acids: Most formulas do not contain citric or phosphoric acids, which are highly corrosive and major culprits behind enamel erosion in many popular sodas.
Different Flavoring Agents: The characteristic taste of root beer comes from sassafras root extract, licorice, nutmeg, and other flavorings, rather than high-acid fruit derivatives.
Often Non-Carbonated: Although carbonation itself introduces carbonic acid, some root beers are traditionally non-carbonated. In cases where they are carbonated, the overall acidity is still buffered by the lack of other major acidifying agents.

A Comparative Look at Soda Acidity

To put root beer's mildness into perspective, it's helpful to compare its typical pH levels to other common soft drinks. While specific values can vary by brand and testing method, a clear pattern emerges.


Beverage Category	Example pH Range	Primary Acidic Components
Root Beer	4.0 - 4.7	Carbonic acid (if carbonated), mild flavoring agents
Colas	2.5 - 3.0	Phosphoric acid, carbonic acid
Diet Colas	3.0 - 3.5	Phosphoric acid, carbonic acid
Lemon-Lime Sodas	3.2 - 3.5	Citric acid, carbonic acid
Flavored Sparkling Water	2.7 - 4.0	Carbonic acid, citric acid from flavorings
Sports Drinks	2.7 - 3.0	Citric acid

The Erosion and Health Implications of Acidic Drinks

The acidity of beverages, measured on the pH scale, directly impacts our dental health. Regular and prolonged exposure to drinks with a pH below 5.5 can lead to irreversible enamel erosion. This weakens the tooth's outer layer, leading to sensitivity, discoloration, and an increased risk of cavities. The key takeaway is that the lower the pH, the more aggressive the acid is. As a logarithmic scale, a pH of 3.0 is ten times more acidic than a pH of 4.0. This makes the difference between a cola at pH 2.5 and a root beer at pH 4.0 extremely significant for your teeth.

For individuals with sensitive stomachs or acid reflux (GERD), highly acidic carbonated beverages can be a major trigger. The carbonation increases stomach pressure, forcing acid up into the esophagus. Choosing less acidic options like root beer can help mitigate these symptoms, though many medical professionals still recommend non-carbonated, non-acidic alternatives like herbal tea, coconut water, or water itself.

Tips for Reducing Your Acid Intake from Beverages

While root beer offers a less acidic soft drink choice, the best way to protect your teeth and stomach is to reduce your overall consumption of acidic drinks. Here are a few strategies:

Drink in moderation: Enjoy sodas and other acidic beverages with meals rather than sipping them throughout the day. This minimizes the prolonged exposure to acid.
Use a straw: Drinking with a straw helps bypass the teeth, reducing the beverage's contact with your enamel.
Rinse with water: Swish with plain water after drinking a soft drink to help neutralize the acids and rinse them away.
Wait to brush: Do not brush your teeth immediately after consuming an acidic drink, as this can scrub the softened enamel. Wait at least 30 minutes to allow your saliva to naturally re-harden your teeth.
Consider low-acid alternatives: Unsweetened teas, milk, and water are the best choices for hydration with the lowest acid content.

Disclaimer: While root beer is the least acidic among standard soft drinks, it still contains sugar and is not considered a healthy drink. The best beverage choices for dental health are plain water and milk.

Conclusion

In summary, the quest for the least acidic soft drink leads directly to root beer, which achieves its flavor without the use of aggressive phosphoric or citric acids. While its pH is still low enough to be erosive over time, it is significantly less damaging than popular colas and citrus-based sodas. However, for those concerned about dental health or acid reflux, the healthiest choices remain water, milk, and herbal teas, as all soft drinks carry some level of risk. Making informed beverage choices and adopting smart drinking habits can help protect your long-term health.

Optional Outbound Link

For more detailed information on beverage acidity and its effect on dental health, the National Institutes of Health provides excellent resources based on scientific research.

Frequently Asked Questions

The soft drinks with the lowest pH values (most acidic) are typically colas, like Coca-Cola and Pepsi, which contain phosphoric acid and have pH levels around 2.5.

Regular Coke and Pepsi tend to be slightly more acidic than their diet counterparts. For example, regular Coke often has a pH around 2.5, while Diet Coke is closer to 3.0.

Root beer is often cited as the least harmful soft drink for teeth because it has the lowest acidity and usually lacks the harsh acids found in other sodas. However, its sugar content means it is still not considered beneficial for dental health overall.

Yes, sparkling water contains carbonic acid, which forms when carbon dioxide is dissolved in water. This gives it a mildly acidic pH, typically around 4.0. Flavored sparkling waters are often more acidic due to added citric acid.

For those with acid reflux, the best drinks are non-carbonated and non-acidic, such as water, ginger tea, or plant-based milks. The carbonation and acidity in most soft drinks can trigger or worsen symptoms.

While root beer is less acidic than many other sodas, its carbonation can still trigger acid reflux symptoms in some people by increasing stomach pressure. Non-carbonated alternatives are generally better for managing reflux.

To reduce the effects of acidic soft drinks, you can use a straw to minimize contact with your teeth, drink them quickly and in moderation, and rinse your mouth with water afterward.