Nearly all fruits are acidic, with pH values ranging from 2.0 (lemons and limes) up to about 5.0 for most common varieties. Only a handful of fruits, like bananas, melons, and avocados, cross into near-neutral territory. Understanding where specific fruits fall on the pH scale matters if you’re managing acid reflux, protecting your tooth enamel, or simply curious about why some fruits make your mouth pucker.
How Fruit Acidity Is Measured
The pH scale runs from 0 to 14, with 7 being neutral. Anything below 7 is acidic, and anything above is alkaline. Most fruits land somewhere between 2.0 and 5.0, making them mildly to strongly acidic. The lower the number, the more acidic the fruit.
The tartness you taste comes from organic acids naturally present in fruit. The two most common are citric acid and malic acid, which together account for the bulk of acidity in nearly every fruit you eat. Citric acid dominates in citrus fruits, making up more than 90% of the total acid in citrus juice. Malic acid is the primary acid in apples, peaches, and cherries. Grapes are the exception: their signature acid is tartaric acid, which also plays a central role in wine’s flavor.
Citrus Fruits: The Most Acidic
Citrus fruits sit at the bottom of the pH scale among common produce. Lemons and limes are the most acidic fruits you’ll encounter, with pH values between 2.0 and 2.8. Their juice contains roughly 48 grams of citric acid per liter for lemons and 46 grams per liter for limes, which translates to about 8% of the dry fruit weight. That concentration is why lemon juice stings a cut and can strip mineral buildup from a faucet.
Grapefruit comes in at pH 3.0 to 3.75, noticeably less acidic than lemons but still strongly tart. Oranges are the mildest of the common citrus fruits, ranging from pH 3.30 to 4.34 depending on the variety and whether you’re drinking juice or eating the whole fruit. Florida oranges tend to land slightly higher on the pH scale than California varieties.
Berries, Grapes, and Pomegranates
Berries are more acidic than many people expect. Blueberries, often thought of as mild, actually have a pH of just 3.12 to 3.33. Strawberries range from 3.0 to 3.90, and raspberries fall between 3.22 and 3.95. Blackberries are the least acidic of the common berries, at 3.85 to 4.50. Loganberries, a raspberry-blackberry cross, can dip as low as 2.70.
Grapes are surprisingly acidic. Concord grapes measure pH 2.80 to 3.00, and even seedless table grapes range from 2.90 to 3.82. Pomegranates are in the same territory, at 2.93 to 3.20, making them one of the more acidic fruits outside the citrus family.
Stone Fruits and Pome Fruits
Stone fruits span a wide range. Blue plums are quite acidic at pH 2.80 to 3.40, while red plums are milder at 3.60 to 4.30. Peaches fall between 3.30 and 4.05, and apricots have one of the widest ranges of any fruit, from 3.30 to 4.80 depending on ripeness and variety. Cherries and nectarines hover around pH 4.0, making them among the least acidic stone fruits.
Apples are moderately acidic, typically ranging from pH 3.30 to 4.00. Variety matters quite a bit here: a tart Jonathan apple measures 3.33, while a sweet Delicious apple comes in at 3.9. Pears are slightly less acidic than apples, with Bartlett pears ranging from 3.50 to 4.60. Pineapple, though not a pome fruit, falls in a similar range at 3.20 to 4.00.
Fruits That Are Low in Acid
If you’re looking for fruits that aren’t strongly acidic, your options are limited but meaningful. Bananas range from pH 4.50 to 5.20, placing them well above most fruits on the scale. Watermelon falls between 5.18 and 5.60. Papayas span 5.20 to 6.00, and figs range from 5.05 to 5.98.
The least acidic fruits are melons and avocados. Cantaloupe measures pH 6.13 to 6.58, and honeydew melon ranges from 6.00 to 6.67, making them nearly neutral. Avocados top the list at pH 6.27 to 6.58. Green (unripe) mangoes are also relatively low-acid at 5.80 to 6.00, though ripe mangoes drop significantly to 3.40 to 4.80.
Ripeness Changes the pH
A fruit’s acidity isn’t fixed. As fruit ripens, its organic acid content decreases and its pH rises. Research on tomatoes found that fruit left on the vine after ripening increased in pH by 0.01 to 0.02 units per day, driven by a steady loss of citric acid. The same principle applies broadly: a green banana is more acidic than a spotted one, and a rock-hard peach is more tart than one that’s soft and fragrant. This is why the pH ranges for many fruits are so wide. A barely ripe strawberry at pH 3.0 and a very ripe one at 3.9 are practically different foods in terms of tartness.
Why Fruit Acidity Matters for Your Teeth
Tooth enamel begins to soften and erode when exposed to anything with a pH of 5.5 or lower. That means virtually every fruit on this list, with the exception of melons and avocados, falls below the threshold for enamel safety. Citrus juices, pomegranates, and grapes are the biggest concerns because they combine very low pH with prolonged contact when you sip juice throughout the day.
The practical takeaway: eating whole fruit is better for your teeth than drinking fruit juice, because chewing stimulates saliva that helps neutralize acid. If you do drink citrus juice, using a straw reduces contact with your teeth. Rinsing your mouth with water afterward helps, but wait at least 30 minutes before brushing, since brushing while enamel is softened from acid exposure can cause more damage.
Fruit Acidity and Acid Reflux
Citrus fruits and tomatoes are among the most commonly reported food triggers for acid reflux and GERD symptoms. The mechanism isn’t just about the acid itself irritating the esophagus. These foods can also trigger increased stomach acid production, which worsens reflux in people who are already prone to it.
Bananas are one of the few fruits that may actually help. They’re low in acid, rich in a soluble fiber called pectin that keeps food moving through the digestive tract, and they can generate a protective coating on the esophageal lining. Melons, papayas, and figs are also generally well tolerated because of their higher pH values.
Acidic pH vs. Acid-Forming in the Body
A fruit’s pH in the kitchen is not the same as its effect on your body after digestion. Researchers use a score called PRAL (potential renal acid load) to estimate how foods affect your body’s acid balance after they’re metabolized. The formula accounts for protein, phosphorus, potassium, magnesium, and calcium content. Fruits are rich in potassium and magnesium, which produce alkaline byproducts during metabolism. So despite being acidic on the pH scale, nearly all fruits have a negative PRAL score, meaning they have an alkalizing effect on the body. A lemon with a pH of 2.0 becomes alkaline once your body processes it. This distinction matters if you’re reading about “alkaline diets,” since the food’s raw pH tells you nothing about its metabolic effect.