Both tea and coffee contain caffeine, which can have a stimulating effect on the body, but can the acidity of these beverages have an impact on our digestive and oral health? This article will explore the science behind the acidity levels of tea and coffee and how they can affect our bodies.
Table of Contents
Acidity of tea vs Coffee: Which is more acidic?
Black coffee and black tea have almost identical levels of acidity. Coffee has an average pH of 4.5 – 6, and black tea has a pH of 4.9 – 5.5.
Liquid | pH |
---|---|
Black Coffee | 4.5-6 |
Black Tea | 4.9-5.5 |
Herbal Tea | 6-7 |
Green Tea | 7-10 |
Green tea, on the other hand, has an average pH of 10, making it 100,000 times less acidic than black tea. Don’t believe me? Keep reading.
When We Say a Drink Is ‘Acidic,’ What Does That Mean?
When we say “acid content” of coffee or tea, we mean that there are tiny particles in these drinks that can make them taste a bit sour or tangy.
The acidity of coffee is due to the presence of organic acids like chlorogenic acid, quinic acid, and citric acid, which contribute to the beverage’s flavor and aroma.
This is why we call it “acidic,” because it tastes similar to foods like lemons or vinegar, which also taste sour. We can taste the acid content in coffee, but it’s usually pretty subtle. Some people might not even notice it.

Understanding pH and Its Relationship to Acidity in Beverages
Let’s nerd out a bit, dive a little deeper, and broaden our understanding of acid, aka pH.
What is pH?
pH is a way to check if something is an acid or a base. It’s measured on a scale from 0 to 14, where 0 is super acidic, 7 is neutral, and 14 is super basic (alkaline).
When something has a pH below 7, it is an acid; when it has a pH above 7, it is a base. The pH scale works in “logarithmic units.” Each whole number represents a 10-fold change1 in acidity or alkalinity.

For example, something with a pH of 4 is 10 x more acidic than something with a pH of 5. And something with a pH of 10 is 10 x less acidic than something with a pH of 9.
Here’s a table showing the pH levels of common everyday liquids:
Liquid | pH |
---|---|
Stomach Acid | 1.5-2 |
Soda | 2.5 |
Vinegar | 2.9 |
Orange Juice | 3.5 |
Romulan Ale 👽 | 4 |
Black Coffee | 4.5-6 |
Black Tea | 4.9-5.5 |
Urine | 6 |
Pure Water | 7 |
Blood | 7.3-7.5 |
Sea Water | 7.7-8.3 |
Baking Soda | 8.4 |
Hand Soap | 9-10 |
Bleach | 12.5 |
Are coffee and tea bad for your stomach?
There is no concrete evidence2 that drinking coffee or tea has long-term negative effects on the stomach.

However, since coffee and certain teas can stimulate stomach acid production3, individuals with sensitive stomachs may be more affected by the acids present in these beverages.
So, all in all, neither coffee nor tea is bad for your stomach.
Does tea or coffee cause GERD, acid reflux, or EE?
A study on coffee4 conducted in 2019 and published in the Journal of Medicine examined the impact of drinking coffee at least four days a week on 1837 participants.
Results showed that drinking coffee (with or without cream) does not cause GERD, acid reflux, or erosive esophagitis (EE).
The same goes for tea. According to at least 30 studies, there is zero association between tea drinking and GERD5.
“The result of meta-analysis showed that tea drinking had no significant association with the risk of GERD.”
Cao, H., Huang, X., Zhi, X., Han, C., Li, L., & Li, Y. (2019)
does coffee affect digestion?
A recent study6 shed light on some interesting findings about coffee consumption. Here are five key takeaways:
- Coffee doesn’t improve digestion.
- Coffee isn’t linked to indigestion.
- Coffee doesn’t usually cause stomach discomfort.
- Coffee can help you poop.
- Caffeine in coffee may lower liver cancer risk 7.
Everyone’s body is unique, so what works for one person may not work for another. It’s important to keep this in mind when it comes to coffee and its effects on our health.

Are coffee and tea bad for your teeth?
Yes and no.
A big study looked at 10 smaller studies about coffee and tea and their relation to tooth health. Out of those 10, 5 studies found that drinking coffee could be bad for your teeth. But, 4 other studies found that drinking coffee every day can actually help protect your teeth from getting damaged.
“The effect of coffee consumption on periodontal health was fragmented since coffee has complex components that may give either beneficial effects or negative impact on periodontal health.”
National Library of Medicine
Good news for coffee lovers! Cold brew coffee is less acidic than hot-brewed coffee, which makes it a better choice if you have sensitive teeth or a sensitive stomach.
Note: Consider trying low-acidity single-origin Sumatra coffee if you struggle with regular coffee’s acidity. Check out my top 10 favorite Sumatran coffee beans in my recent post here.

Is coffee good for you?
Coffee offers several health benefits, particularly anti-inflammatory and antioxidant effects, that can help protect against diseases and potentially promote longevity.
A recent umbrella study8 of multiple coffee-related studies showed that drinking at least 3 cups of coffee plays a major role in reducing deaths from cardiovascular disease, coronary heart disease, and strokes.
Outcome | Risk Reduction | Optimal Intake |
---|---|---|
All cause mortality | 10% lower risk | 3 cups/day |
Cardiovascular disease mortality | 19% lower risk | 3 cups/day |
Coronary heart disease mortality | 16% lower risk | 3 cups/day |
Stroke mortality | 30% lower risk | 3 cups/day |
Cardiovascular disease mortality (per cup increase) | 2% lower risk | N/A |
Is tea good for you?
Tea comes in various flavors and types, from black and white tea to fruit and herbal teas. While tea also contains caffeine, it’s often consumed for its health benefits.
According to a recent study9 that involved 500,000 tea drinkers in the UK, those who drank at least two cups of tea daily had a 9% to 13% lower risk of death from any cause compared to those who did not drink tea. In addition, increased tea consumption was linked to the following:
- weight loss
- lower risk of death from cardiovascular disease
- lower risk of death from ischemic heart disease
- lower risk of death from stroke
Tea also has less caffeine compared to coffee. This can make it a better option for those who are sensitive to caffeine or have trouble sleeping after drinking coffee.
Tea also contains antioxidants, which can help protect the body against damage from free radicals and reduce the risk of chronic diseases.
FAQ
Which teas have the lowest acidity?
Fruit teas, chamomile tea, rosehip tea, and mint tea are some of the least acidic teas available. The level of acidity in tea depends on the type of tea, with black and oolong teas being more acidic than herbal and fruit teas. Lemon tea and iced teas are also acidic, as they contain added fruit juices.
Which coffee has the lowest acidity?
The acidity level in coffee can vary depending on factors such as the type of coffee bean, roast level, and brewing method. However, overall, the acidity levels of coffee don’t vary too much. Generally, darker roasts tend to have lower acidity levels than lighter roasts. Some coffee brands also market “low-acid” coffee, which has been processed to reduce acidity levels.
Conclusion
In summary, while coffee and tea do not appear to have a significant impact on our digestive health, their effects on oral health are still uncertain. Coffee tends to have an acidity level of around 5 on the pH scale, whereas the acidity of tea varies depending on the type.
It’s worth noting that both coffee and tea have been shown to help lower the risk of death from heart disease, cardiovascular disease, and stroke. Nonetheless, moderation is key when consuming these beverages.
Key Takeaways:
- Black coffee and tea have similar acidity levels.
- Unclear if coffee or tea is bad for your teeth.
- No impact of coffee/tea on digestion.
- Coffee/tea lower mortality from cardiovascular disease, heart disease, and stroke.
References
- https://www.usgs.gov/special-topics/water-science-school/science/ph-and-water#:~:text=oil%20or%20alcohol.-,pH%20is%20a%20measure%20of%20how%20acidic%2Fbasic%20water%20is,hydroxyl%20ions%20in%20the%20water.
- Wei, Y., Hsueh, H., Wen, H., Chen, L., & Wang, C. (2019). The role of tea and coffee in the development of gastroesophageal reflux disease. Tzu-Chi Medical Journal, 31(3), 169-176. https://doi.org/10.4103/tcmj.tcmj_48_18
- Boekema PJ, Samsom M, van Berge Henegouwen GP, Smout AJ. Coffee and gastrointestinal function: facts and fiction. A review. Scand J Gastroenterol Suppl. 1999;230:35-9. doi: 10.1080/003655299750025525. PMID: 10499460.
- Wei, Y., Hsueh, H., Wen, H., Chen, L., & Wang, C. (2019). The role of tea and coffee in the development of gastroesophageal reflux disease. Tzu-Chi Medical Journal, 31(3), 169-176. https://doi.org/10.4103/tcmj.tcmj_48_18
- Cao, H., Huang, X., Zhi, X., Han, C., Li, L., & Li, Y. (2019). Association between tea consumption and gastroesophageal reflux disease: A meta-analysis. Medicine, 98(4). https://doi.org/10.1097/MD.0000000000014173
- Boekema PJ, Samsom M, van Berge Henegouwen GP, Smout AJ. Coffee and gastrointestinal function: facts and fiction. A review. Scand J Gastroenterol Suppl. 1999;230:35-9. doi: 10.1080/003655299750025525. PMID: 10499460.
- Boekema PJ, Samsom M, van Berge Henegouwen GP, Smout AJ. Coffee and gastrointestinal function: facts and fiction. A review. Scand J Gastroenterol Suppl. 1999;230:35-9. doi: 10.1080/003655299750025525. PMID: 10499460.
- Poole, R., Kennedy, O. J., Roderick, P., Fallowfield, J. A., Hayes, P. C., & Parkes, J. (2016). Coffee consumption and health: Umbrella review of meta-analyses of multiple health outcomes. The BMJ, 359. https://doi.org/10.1136/bmj.j5024
- Inoue-Choi M, Ramirez Y, Cornelis MC, et al. Tea Consumption and All-Cause and Cause-Specific Mortality in the UK Biobank: A Prospective Cohort Study. Ann. Intern. Med. August 30, 2022. DOI: 10.7326/M22-0041