What's More Acidic, Coffee or Black Tea? Unpacking the pH Balance

December 13, 2025 •

4 min read

According to scientific data, a typical cup of brewed coffee generally has a lower pH level, making it more acidic than black tea. For individuals with sensitive stomachs or acid reflux, understanding this key difference is critical to managing symptoms and choosing the right beverage for their health.

Quick Summary

This guide compares the acidity of coffee and black tea, detailing their respective pH levels and the factors that influence them. It explores the different acids present in each drink, their potential health impacts, and provides practical tips on how to reduce acidity during preparation.

Key Points

Coffee is more acidic: On average, coffee has a lower pH (higher acidity) than black tea.
Brewing matters: The roast level of coffee and the steeping time of tea are major factors that influence their final acidity.
Cold brew is the gentlest: The cold brew method for coffee significantly reduces acidity, making it a better choice for sensitive stomachs.
Acids are different: Coffee's acidity comes from compounds like chlorogenic and citric acids, while black tea's is mainly from tannins.
Additives can help: Adding milk or cream can help buffer and reduce the acidity in both coffee and tea.
Health effects vary: Coffee is more likely to trigger acid reflux than tea for sensitive individuals.
Herbal teas are low acid: Most herbal infusions are less acidic than black tea, with some like chamomile having a nearly neutral pH.

Demystifying the pH Scale

The pH scale is a fundamental concept in chemistry used to measure the acidity or alkalinity of a substance. Ranging from 0 to 14, a pH of 7 is considered neutral, like pure water. Anything below 7 is acidic, with lower numbers indicating higher acidity, while a pH above 7 is alkaline. The scale is logarithmic, meaning a single-point drop, such as from pH 5 to 4, represents a tenfold increase in acidity. For example, highly acidic lemon juice has a pH of around 2, while milder black tea typically falls in the 4.9 to 5.5 range, and coffee averages between 4.85 and 5.4.

The Acidity Profile of Coffee

Coffee is known for its complex and diverse flavor profile, and its acidity plays a crucial role in this. The acidity in coffee comes from several naturally occurring acids, including chlorogenic, citric, malic, quinic, and acetic acids. The final pH level is influenced by several factors:

Bean Type: Arabica beans generally contain more chlorogenic and citric acids than Robusta beans, making them more acidic. Choosing a Robusta blend can result in a less acidic cup.
Roast Level: Darker roasts are typically less acidic than lighter roasts. The high temperatures and longer roasting times break down the acidic compounds in the bean, resulting in a higher pH.
Brewing Method: The brewing method significantly impacts acidity. Cold brewing, for example, extracts fewer acidic compounds than a hot brew, resulting in a smoother, less acidic cup with a higher pH. Other methods like French press and AeroPress can also produce lower-acidity coffee.
Water Quality: The mineral content of the water used for brewing can affect the final pH. Water with higher mineral content can increase the coffee's pH, making it less acidic.
Additives: The addition of milk or cream can raise the pH level of coffee, as dairy products are close to neutral on the pH scale and contain buffering proteins.

The Acidity Profile of Black Tea

Black tea is produced by fully oxidizing the leaves of the Camellia sinensis plant, a process that changes its chemical composition and increases the concentration of certain acidic compounds. The primary acid compounds contributing to black tea's acidity are tannins, which also impart the characteristic astringent flavor. Key factors affecting its acidity include:

Steeping Time: The longer you steep black tea, the more tannins and other acidic compounds are released from the leaves, leading to a more acidic beverage. Shortening the brew time is an effective way to lower acidity.
Preparation Temperature: Higher temperatures can lead to a faster and more thorough extraction of tannins. Using a slightly lower temperature for brewing or opting for cold brewing can produce a less acidic tea.
Additives: Similar to coffee, adding milk or a dash of baking soda can neutralize the acidity in black tea. Adding citrus fruits like lemon, however, will make it significantly more acidic.
Oxidation Level: Black tea is more acidic than less-oxidized green or white teas, which often have pH levels closer to neutral.

Acidity Comparison: Coffee vs. Black Tea

While exact pH can vary based on numerous factors, this table provides a general comparison of the two beverages. It's important to remember that these are average ranges and not absolute values.


Feature	Coffee	Black Tea
Average pH Range	4.85–5.4	4.9–5.5
Relative Acidity	Generally more acidic	Generally less acidic
Primary Acid Source	Chlorogenic, citric, malic, quinic, acetic acids	Tannins
Effect on Reflux	More likely to trigger or worsen symptoms for sensitive individuals	Less likely to trigger symptoms, especially when brewed gently
How to Reduce Acidity	Darker roast, colder brew, adding milk, coarser grind	Shorter steep time, adding milk, 'quick rinse' method

Health Implications for Sensitive Stomachs

For many, the slight difference in pH between coffee and black tea is insignificant. However, for those with conditions like acid reflux (GERD) or gastritis, the choice can be crucial. Studies have found that coffee, in contrast to tea, can increase gastro-oesophageal reflux. This effect is not solely due to caffeine, as decaffeinated coffee still showed a reflux increase, albeit less pronounced. Both beverages contain caffeine, which can relax the lower esophageal sphincter and contribute to reflux symptoms. However, black tea is often tolerated better, and its acidity is easier to modify than coffee's.

How to Reduce Acidity in Your Brew

If you suffer from acid sensitivity but don't want to give up your favorite morning ritual, there are several effective strategies:

For Coffee: Consider switching to a dark roast coffee, which naturally has less acid than light or medium roasts. The cold brew method is another excellent option for a significantly smoother, less acidic cup. Adding a splash of milk or cream can also act as a buffer and raise the pH.
For Black Tea: Reduce your steeping time to just 1–2 minutes to extract fewer tannins. Brewing in colder water is another effective technique. You can also add milk, as the proteins can bind with the tannins and neutralize the acidity, resulting in a milder flavor.

For those with severe sensitivity, opting for herbal teas like chamomile or peppermint, which are naturally lower in acid, is a great alternative. Regardless of your choice, paying attention to how your body responds is key.

Conclusion

While both coffee and black tea are mildly acidic, coffee is generally the more acidic of the two. However, the impact on your health depends less on the simple pH number and more on your individual sensitivity and how you prepare your beverage. For those concerned about acid reflux or stomach irritation, black tea often presents a gentler alternative, especially since its acidity is easier to modify. Ultimately, understanding the science behind your favorite beverage empowers you to make informed choices that align with your health and wellness goals. For more on the effect of beverages on gastro-oesophageal reflux, a 1995 study offers further insights.

Frequently Asked Questions

Decaf coffee is often less acidic than a standard brew, especially depending on the roasting process. However, some decaffeination methods only slightly alter the acidity, so the effect might be less pronounced than switching to a darker roast or cold brew.

Yes, adding milk or cream is an effective way to reduce the acidity of both coffee and tea. Milk is nearly neutral on the pH scale and contains proteins that can buffer the acidic compounds, resulting in a milder beverage.

The cold brew method produces the least acidic coffee. By steeping coffee grounds in cold water over a long period, fewer acidic compounds and oils are extracted, leading to a smoother, sweeter, and less acidic taste.

Yes, frequent consumption of acidic drinks can contribute to tooth enamel erosion over time, especially if the pH is below 4. However, the British Dental Journal found that enamel pH can recover quickly after drinking black tea, suggesting a lower risk compared to much more acidic drinks like soda.

For individuals with acid reflux, black tea is generally a better choice than coffee. Studies show that coffee increases gastro-oesophageal reflux more significantly than tea. Both contain caffeine, which can be a trigger, but black tea is milder and its acidity is more easily controlled.

Darker roasts of coffee are less acidic than lighter roasts. The longer and higher-temperature roasting process breaks down more of the acidic compounds in the coffee beans, resulting in a higher pH and a less sharp flavor.

To make black tea less acidic, try shortening your steeping time to 1-2 minutes, use the cold brew method, or add milk. A 'quick rinse' of the tea leaves with hot water before the main steep can also help remove some of the initial acidic compounds.