Demystifying Tea: What Kind of Acid is in Tea and How It Affects Your Nutrition Diet

October 13, 2025 •

3 min read

Though many people consider tea a mild beverage, most teas have a slightly acidic pH level, containing a variety of organic acids. The primary compounds that dictate what kind of acid is in tea are polyphenols known as tannins, along with other organic acids like oxalic and citric acid. The type and concentration of these acids have important implications for your health, digestion, and overall nutrition plan.

Quick Summary

Tea contains tannins and other organic acids, such as oxalic and citric acid, which affect its flavor, health impacts, and acidity. Acidity levels vary by tea type and preparation, with potential impacts on digestion, mineral absorption, and overall wellness.

Key Points

Tannins are the main acidic compounds in tea: These polyphenols cause the bitterness and astringency and their concentration is influenced by the tea's processing.
Acidity varies by tea type: Black tea is typically the most acidic, while green and white teas are milder due to their lower oxidation levels.
Oxalic acid is present in tea: Though generally low in bioavailability, it is a concern for those prone to kidney stones and is more concentrated in black and dark teas.
Tea's acidity can affect digestion: High levels of tannins or drinking on an empty stomach can cause stomach irritation in sensitive individuals.
Acids in tea can hinder iron absorption: Tannins bind to plant-based iron, potentially impacting absorption. Drinking tea between meals can help mitigate this effect.
Brewing techniques can reduce acidity: Shorter steep times and lower water temperatures can minimize the extraction of acidic compounds, resulting in a milder cup.
Herbal teas vary in acidity: While many are low in tannins, fruit-based herbal teas like hibiscus can be highly acidic.

The Primary Acids in Tea

Tea leaves contain various natural acids that contribute to its flavor, color, and properties. These are mainly polyphenols.

Tannins: These polyphenols are well-known for giving tea its bitter taste and astringent feel. Black tea's oxidation process increases tannins like theaflavins and thearubigins, derived from catechins. Note that "tannic acid" is often a misnomer.
Oxalic Acid: Present in tea leaves, oxalates can be a concern for those prone to kidney stones due to their calcium-binding properties. Oxalic acid levels vary by tea type, with darker teas usually having more, though oxalate bioavailability from tea is generally low.
Citric and Malic Acid: These common organic acids add sour notes and are influenced by the tea plant's variety, growth, and processing.
Other Organic Acids: Tea contains over 40 identified organic acids, including gallic, succinic, and lactic acids, which affect flavor and plant metabolism.

Acidity Levels Across Different Tea Types

Tea processing significantly impacts acidity, resulting in various pH levels from the Camellia sinensis plant.


Tea Type	Typical pH Range	Oxidation Level	Acidity Notes
Black Tea	4.9–5.5	Fully Oxidized	Highest acidity due to high tannin concentration.
Oolong Tea	5.5–7.0	Partially Oxidized	Moderate acidity.
Green Tea	7.0–10.0	Unoxidized	Least acidic, potentially slightly alkaline.
White Tea	6.9–9.7	Minimally Oxidized	Low acidity.
Herbal Tea (Tisanes)	Varies widely	N/A	Acidity depends on ingredients; fruit teas are typically high.

Impact on Digestion and Nutrient Absorption

Tea's acids can affect nutrition positively and negatively depending on consumption.

Potential Benefits

Antioxidant Effects: Polyphenols like tannins act as antioxidants, potentially reducing chronic disease risk.
Promotes Gut Health: Organic acids and polyphenols may regulate gut bacteria.
Supports Digestion: Some organic acids might stimulate digestive enzymes.

Potential Drawbacks

Digestive Discomfort: High tannins can irritate the stomach lining, especially on an empty stomach.
Iron Absorption Interference: Tannins can reduce the absorption of non-heme iron.
Dental Health: Acidity and tannins can contribute to tooth staining.

How to Manage Tea Acidity for Your Diet

Moderate tea consumption is generally safe. For sensitivity, managing acidity is possible.

Brewing and Preparation Techniques

Reduce Steeping Time: Shorter steeping extracts fewer tannins and less acidity.
Use Cooler Water: Limits tannin extraction in green/white teas.
Add Milk: Milk proteins can bind tannins, reducing astringency and iron absorption impact.
Time Your Tea: Drinking between meals minimizes impact on iron absorption.

Choosing the Right Tea

Opt for Lighter Teas: Green and white teas are lower in tannins and acidity.
Select Lower-Oxalate Teas: Green tea has lower oxalates than black and dark teas.
Explore Herbal Options: Many herbal teas are low in tannins; fruit teas can be highly acidic.

General Consumption Guidelines

Moderate Consumption: Limiting intake is advised.
Consume with Food: Pairing with a meal can buffer the stomach.
Listen to Your Body: Adjust based on discomfort.

Conclusion

Understanding what kind of acid is in tea reveals compounds affecting taste and health. Tannins offer flavor and antioxidants but can impact digestion or mineral absorption. By selecting teas and adjusting brewing based on needs and sensitivities, you can enjoy tea's benefits while minimizing drawbacks and integrating it into a healthy nutrition diet. For more on polyphenols, consult the National Institutes of Health.

Frequently Asked Questions

Yes, tea contains a variety of organic acids. While tannins (polyphenols) are the most significant, other notable acids include oxalic acid, citric acid, malic acid, and gallic acid, all contributing to the flavor and nutritional profile.

Yes, black tea is generally more acidic than green tea. This is because black tea is fully oxidized during processing, which converts catechins into more acidic tannins like theaflavins and thearubigins. Green tea undergoes minimal oxidation, resulting in a higher, less acidic pH.

For some people, drinking strong tea on an empty stomach can cause digestive discomfort. The tannins and caffeine can increase stomach acid production and irritate the stomach lining, potentially leading to heartburn, bloating, or nausea.

To reduce the acidity and astringency of your tea, you can try reducing the steeping time, using slightly cooler water, or adding milk. The proteins in milk bind with tannins, neutralizing some of the effects.

Oxalic acid in tea can bind with calcium, potentially interfering with its absorption. However, consuming moderate amounts of tea with a varied diet is unlikely to cause a significant issue for most people.

Individuals with acid reflux or sensitive stomachs may benefit from lower-acid options like certain green teas, white tea, or low-acid herbal teas such as chamomile or rooibos.

Yes, tea can stain teeth, particularly darker varieties like black and oolong. The tannins bind to tooth enamel and attract pigments, leading to discoloration over time. Practicing good oral hygiene and rinsing with water after drinking can help minimize staining.