Tea Story

Is tea acidic? Yes, most tea is mildly acidic, with a pH below 7. In published lab measurements, brewed black tea sits around pH 4.6 to 5.0, green and white tea around 5.4 to 5.5, and peppermint tea close to neutral at about 6.3. The truly acidic teas are hibiscus blends and bottled iced teas with added citric acid, which can drop below pH 3, as acidic as many soft drinks.

Is tea acidic or basic?

Tea is acidic, not basic (alkaline). The pH scale runs from 0 to 14. Pure water is 7, which is neutral. Anything below 7 is acidic and anything above 7 is alkaline. The scale is logarithmic, so a drink at pH 5 is ten times more acidic than one at pH 6.

Plain brewed tea gets its mild acidity from natural compounds in the leaf, mainly polyphenols (including tannins) and small amounts of organic acids. That is why the answer to “is tea acidic” is yes for every true tea.

You will see claims online that green tea is “alkaline” or has a pH of 7 to 10. We could not find a study that supports that. Measured green tea is mildly acidic, just less so than black tea.

Is tea acidic? pH of tea by type, from published measurements

Most pH charts online are copied from each other without a source. The numbers below come from lab studies. Your cup will vary with the tea, water and steeping time, so treat them as typical values.

Drink	Measured pH	Source and notes
Black tea, brewed	about 4.6 to 5.0	Median 4.63 across 55 black teas (Małyszek et al., Foods, 2025); 5.0 in a 2021 Journal of Dentistry study
Oolong tea, brewed	about 5.0	Median 4.97 across 9 oolongs (Małyszek et al., 2025)
White tea, brewed	about 5.4	Median 5.40 across 7 white teas (Małyszek et al., 2025)
Green tea, brewed	about 5.4 to 5.5	Median 5.48 across 27 green teas (Małyszek et al., 2025); 5.4 (Journal of Dentistry, 2021)
Peppermint tea	about 6.3	Journal of Dentistry, 2021, close to the water control at 6.2
Chamomile tea	about 6.4 to 7.1	Reported in lab studies of herbal teas; close to neutral
Rooibos tea	about 4.6	One older laboratory study; data are limited
Hibiscus or rosehip blend	about 2.9	Rosehip tea containing hibiscus (Journal of Dentistry, 2021)
Bottled iced teas (17 US brands)	2.85 to 5.18, average 3.48	Reddy et al., Journal of the American Dental Association, 2016
Lemon flavored bottled tea	about 2.9	Arizona Iced Tea 2.85, Lipton Green Tea with Citrus 2.93 (Reddy et al., 2016)
Brewed coffee	about 5.1	Starbucks medium roast 5.11 (Reddy et al., 2016)
Water	7.0	Neutral reference

Sources: the 2025 survey of 98 leaf teas by Małyszek and colleagues, and the US beverage pH study by Reddy and colleagues.

Is black tea acidic or alkaline?

Black tea is acidic. With a typical pH between about 4.6 and 5.0 in recent measurements, it is the most acidic of the plain teas. In the 2025 survey, black tea was more acidic than oolong, green and white tea by a clear margin.

Still, “most acidic tea” is a low bar. Black tea is far less acidic than cola, fruit juice or lemon flavored bottled tea. A stewed mug with the bag left in will be a bit more acidic than a three minute brew.

Is herbal tea acidic?

It depends entirely on the plant. “Herbal tea” covers everything from mint to dried fruit, and one older study found herbal teas ranging from pH 3.1 to 7.1.

• Peppermint tea is close to neutral at about pH 6.3. So is peppermint tea acidic or alkaline? Slightly acidic, but barely. Our guide to peppermint tea and hydration covers its other effects.
• Chamomile is close to neutral and one of the gentlest options.
• Rooibos has little published pH data; one older study measured about 4.6. It is caffeine free and low in tannins. See our rooibos tasting guide.
• Hibiscus, rosehip and fruit blends are the acidic ones, often below pH 3. Their sour taste is a good clue.

Is iced tea acidic?

Homemade iced tea has about the same pH as the hot tea it was brewed from. Bottled iced tea is another story.

In the US study of beverages, 17 bottled teas ranged from pH 2.85 to 5.18, with an average of 3.48. Many have citric acid or lemon flavor added for taste and shelf life, which pushes them into the same range as soft drinks. The study’s authors class drinks below pH 3 as “extremely erosive” and those from 3 to 3.99 as “erosive” for teeth. Check the label for citric acid if you drink bottled tea often. For caffeine in the same drinks, see how much caffeine is in iced tea.

Which is more acidic, coffee or tea?

It depends on the tea. In published measurements, brewed coffee sits around pH 5.1, and plain black tea lands in about the same range, from 4.6 to 5.0. So is black tea less acidic than coffee? Not by much, and some measurements put it slightly more acidic.

Green tea, white tea, peppermint and chamomile are less acidic than coffee. Bottled lemon iced tea is much more acidic.

pH is not the whole story for your stomach, though. Coffee usually has about twice the caffeine of black tea, and caffeine can affect reflux in some people.

Is tea acidic enough to hurt tooth enamel?

Tooth enamel starts to soften when your mouth is more acidic than about pH 5.5, and the risk climbs sharply below pH 4. Plain brewed tea mostly sits above 4, so the risk from an ordinary cup is low.

Plain tea rarely causes problems. Fruity tea sometimes does:

• In a 2013 study of brewed tea bags (Hendricks et al., American Journal of Dentistry), citrus and fruity teas caused enamel lesions about two to four times deeper than black or green tea.
• In the 2021 Journal of Dentistry study, black and green tea gave the best protection against an acid challenge, probably because their polyphenols bind to the thin protein film on teeth. The hibiscus rosehip tea caused erosion.

To protect your teeth, drink fruity or lemon tea with meals, do not swish it around your mouth, use a straw for bottled iced tea, and rinse with water before brushing about 30 minutes later.

Is tea acidic enough to cause acid reflux (GERD)?

The pH of the tea in your cup is not the main issue. Your stomach acid is far stronger, at about pH 1.5 to 3.5. What matters more for reflux is whether a drink relaxes the valve at the top of the stomach or triggers your own symptoms.

The evidence is mixed. A 2019 review that pooled 30 studies (Cao et al., Medicine) found no significant link between tea drinking and GERD overall, though it found a higher risk in East Asian studies.

• Caffeine may trigger reflux in some people, so strong black tea is the most likely culprit.
• Peppermint is close to neutral in pH, but menthol may relax the valve between the stomach and the food pipe, so some people with reflux find it makes heartburn worse.
• Chamomile and rooibos are caffeine free and low in tannins, and many people with reflux tolerate them well.
• An empty stomach makes discomfort more likely, as our guide to feeling sick after tea on an empty stomach explains.

US gastroenterology guidelines suggest avoiding the foods and drinks that trigger your own symptoms rather than cutting out a fixed list.

How milk and lemon change tea’s acidity

• Milk raises the pH. Milk is close to neutral, at about pH 6.4 to 6.8, so adding it to black tea makes the cup less acidic. Milk also adds calcium, which is kind to teeth.
• Lemon lowers the pH. Lemon juice is very acidic, at about pH 2 to 2.6. Even a squeeze pulls a cup of black tea down noticeably, and lemon flavored bottled teas measure around pH 2.9. If you love it, our post on black tea with lemon covers the benefits; just drink it with a meal and rinse after.

How to make tea less acidic

1. Choose a gentler tea: green, white, peppermint or chamomile.
2. Steep for two to three minutes, not until the cup is stewed.
3. Add a splash of milk to black tea.
4. Skip lemon and hibiscus if you have reflux or worn enamel.
5. Brew your own iced tea instead of buying bottles with citric acid.
6. Drink tea with food.

FAQ

Is tea acidic?

Yes, most tea is mildly acidic. Brewed black tea measures about pH 4.6 to 5.0 and green tea about 5.4 to 5.5. Hibiscus blends and bottled iced teas can fall below pH 3.

Is black tea acidic or alkaline?

Black tea is acidic, with a typical pH of about 4.6 to 5.0. It is the most acidic plain tea but much less acidic than soda or juice.

What is the pH of green tea?

Measured green tea is about pH 5.4 to 5.5. It is mildly acidic, not alkaline as some sites claim.

Is peppermint tea acidic or alkaline?

Peppermint tea is close to neutral, at about pH 6.3 in lab tests. It is not very acidic, but menthol may worsen heartburn in some people with reflux.

Is iced tea acidic?

Homemade iced tea has the same pH as hot tea. Bottled iced teas tested in the US ranged from pH 2.85 to 5.18, averaging 3.48, because many contain citric acid.

Which is more acidic, coffee or tea?

Brewed coffee measures about pH 5.1, close to plain black tea. Green, white and herbal teas such as peppermint and chamomile are less acidic than coffee.

Is herbal tea acidic?

It depends on the plant. Peppermint and chamomile are near neutral, while hibiscus, rosehip and other fruit teas are strongly acidic.

Bottom line

Is tea acidic? Yes, but plain tea is only mildly acidic and safe for most people and most teeth. Black tea is the most acidic plain tea and sits close to coffee; green, white, peppermint and chamomile are gentler. The real acid drinks are hibiscus blends, lemon tea and bottled iced teas. Add milk, skip lemon, brew for less time and drink with food if acidity bothers you.

This article is for general information and is not medical advice. If you have frequent heartburn or reflux, talk to your doctor.