Is coffee acidic? Yes, mildly. A 2018 study in Scientific Reports by Niny Rao and Megan Fuller measured the pH of hot-brewed coffee at about 4.85–5.10 and cold brew at about 4.96–5.13 (Rao and Fuller, 2018). For comparison, pure water is neutral at pH 7, and orange juice is more acidic, usually around pH 3.5–4. Coffee can trigger heartburn in some people, but whether it does depends on the person, the amount and the way it is brewed.
Is coffee acidic? What “acidic” means for coffee
“Acidity” in coffee means two different things:
- Chemical acidity: measured by pH and by titratable acidity, which reflects the total amount of acids present. Coffee contains chlorogenic, citric, malic, quinic and other acids.
- Flavor acidity: the bright, tangy or fruity taste coffee tasters describe. A coffee can taste bright without being much more acidic by pH.
The pH scale is logarithmic, so a drink at pH 5 is ten times more acidic than one at pH 6. Even so, coffee sits at the milder end of common drinks.
Coffee pH compared with other drinks
| Drink | Approx. pH |
|---|---|
| Cola soft drinks | About 2.5 |
| Orange juice | About 3.5–4 |
| Hot-brewed coffee | About 4.85–5.10 |
| Cold brew coffee | About 4.96–5.13 |
| Black tea | Roughly 5 |
| Milk | About 6.5–6.8 |
| Water | 7 |
Coffee values are from Rao and Fuller (2018). Other values are typical ranges and vary by product.
Is cold brew less acidic?
Partly. In the 2018 study, cold brew and hot brew had similar pH levels, but hot brew had higher titratable acidity, meaning it contained more total acids. The researchers suggested cold brew is not a guaranteed fix for people with stomach issues, because the pH difference was small. Many people still find cold brew smoother tasting, which can make it more pleasant if you are sensitive to sharp, bright flavors.
If you want to try it, use a coarse grind at about 1:5 to 1:8 coffee to water and steep 12–18 hours in the fridge.
Does roast level change acidity?
Yes, flavor acidity drops as coffee is roasted darker, because some acids, especially chlorogenic acids, break down during roasting. Light roasts taste brighter and more acidic; dark roasts taste mellower. Learn more in our guides to light roast coffee and dark roast coffee. Whether a darker roast is easier on your stomach varies from person to person.
Does brewing method change acidity?
Brewing affects how much acid ends up in the cup, mostly through water temperature, contact time and grind size:
- Hot water extracts acids more readily than cold water, which is why hot brew showed higher titratable acidity than cold brew in the 2018 study.
- Under-extracted coffee, brewed too quickly or too coarsely, often tastes sharp and sour, even though its pH may not be very different. See our guide to sour espresso.
- Paper filters remove oils and fine particles but do not meaningfully change acidity.
- Espresso is concentrated, so a shot tastes more intense, but the serving is small.
Water matters as well. Very soft water can make coffee taste sharper, while moderately mineralized water tends to soften perceived acidity.
Does coffee cause acid reflux?
Coffee does not cause gastroesophageal reflux disease (GERD) on its own, but it can trigger or worsen symptoms in some people. The U.S. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) lists coffee and other sources of caffeine among foods and drinks some people find make GERD symptoms worse, and notes a doctor may suggest reducing them to see if symptoms improve.
At the same time, Mayo Clinic experts say broad, restrictive diets are no longer the norm for managing GERD. Instead, they suggest tracking what you eat and your symptoms to find your own personal triggers.
In other words, coffee is a possible trigger, not a universal one. Some people with reflux tolerate a cup a day well, while others notice symptoms after even small amounts.
Why coffee might trigger heartburn
Researchers have suggested several reasons coffee may bother some people, though the evidence is mixed:
- Caffeine may relax the lower esophageal sphincter, the muscle that keeps stomach contents down.
- Coffee can stimulate stomach acid production.
- Large servings, drinking on an empty stomach, and adding high-fat creamers may add to symptoms.
Tips if coffee bothers your stomach
These general tips may help some people. They are not a substitute for medical advice.
- Track your symptoms to see whether coffee, and how much, is actually a trigger.
- Try smaller servings, such as a single shot or a small cup.
- Drink it with food rather than on an empty stomach.
- Try a darker roast or cold brew, which many people find tastes smoother.
- Consider decaf. If caffeine is your trigger, decaf may help. See decaf espresso for good options.
- Avoid coffee close to bedtime, since lying down soon after drinking can make reflux more noticeable.
- Watch the extras. High-fat creamers, chocolate and mint syrups can also be triggers for some people.
Does adding milk make coffee less acidic?
Milk has a higher pH than coffee, so adding it raises the drink’s pH slightly and softens the taste of acidity. Some people find milky drinks such as lattes gentler. However, milk fat can be a trigger for others, so it is worth testing what works for you. Our guide to latte vs cappuccino vs flat white explains how much milk each drink contains.
Is “low-acid coffee” worth trying?
Some brands sell coffee marketed as low-acid, usually through darker roasting, specific growing regions, or special processing. Results vary, and there is limited independent research on these products. If you try one, compare how you feel against your regular coffee in similar amounts.
When to see a doctor
Occasional heartburn is common. Frequent heartburn, trouble swallowing, chest pain, or symptoms that do not improve with simple changes should be checked by a doctor, who can rule out other causes and recommend treatment.
Is acidic coffee bad for your teeth?
Coffee is less acidic than many soft drinks and juices, but frequent sipping throughout the day can still affect tooth enamel and cause staining. Drinking water afterward and not brushing immediately after acidic drinks are common dental recommendations. Ask your dentist for advice specific to you.
FAQ
What is the pH of coffee?
Brewed coffee usually has a pH of about 4.85–5.13, according to a 2018 study in Scientific Reports. It varies with beans, roast and brewing.
Is coffee more acidic than orange juice?
No. Orange juice is more acidic, usually around pH 3.5–4, compared with about pH 5 for coffee.
Does cold brew have less acid?
Cold brew has a similar pH to hot coffee but lower total titratable acidity in at least one study. Many people find it tastes smoother.
Is decaf coffee acidic?
Yes. Decaf is still mildly acidic, but it removes caffeine, which may be the main trigger for some people.
Can I drink coffee if I have acid reflux?
Many people with reflux can drink some coffee, but it is a common trigger. Track your symptoms and ask your doctor what is right for you.
This article is for general information only. If you have frequent heartburn or reflux, please ask your doctor for personal advice.