While moving across Napa valley, you may find black grapes super tangy in the fall but stunningly sweet in summer. Feeling perplexed?
The taste of grapes can be misleading, as they contain diverse flavors. Tasting sweet, spicy, and sour taste in one single bite will surely make you inquire, are grapes acidic or alkaline?
Grapes are acidic as their pH value ranges from 1.9 to 4. High tartaric, malic, and citric acid concentrations make grapes highly acidic. The fruit can trigger acid reflux if you eat too much of it. Table grapes (3.18 – 3.30) are more acidic than wine grapes (3.15 – 3.45) despite color varieties.
There is more to learn about grapes, their acidity, and how they impact your health. Stay tuned to get all the details.
How Acidic Are Grapes?
Type of Grapes | Varieties | pH | Nature |
Table (thick skin) | Cardinal | 3.47 | Acidic |
Table (thick skin) | Italy | 3.30 | Acidic |
Table (thick skin) | Horoz Karasi | 3.43 | Acidic |
Table (thick skin) | Tekirdag Misketi | 3.31 | Acidic |
Wine (thin skin) | Gamay | 3.34 | Acidic |
Wine (thin skin) | Riesling | 3.29 | Acidic |
Wine (thin skin) | Chardonnay | 3.35 | Acidic |
Wine (thin skin) | Merlot | 3.40 | Acidic |
Are Grapes Acidic Or Alkaline?
The pH value ranges from 2 to 4, which falls into the acidic scale.
No matter which way you consume grapes (I love the wine most, though!), they are acidic. Naturally, grapes are rich in organic acids like:
- Tartaric acid
- Malic acid, and
- Citric acid
Tartaric and malic acid comprise 90% of organic acid found in grapes.

A higher concentration of these natural acids makes grapes acidic or any products from grapes.
Are Red Grapes Acidic or Alkaline?
Red grapes are acidic with a pH value of 3.88. However, they are less acidic than any green or purple grape. Interestingly, red grapes have higher acid content than white or green grapes. But the acids are not strong enough to generate low pH. Winemakers prefer highly sour grapes as the fermentation process will break down the acids to make more sugar.
Are Green Grapes Acidic?
Green grapes are more acidic (pH 2.4) than most other grape varieties. It’s not the color that impacts acidity but the ripe status. Green grapes are unripe, so they contain more acid. Less sugar makes them super sour than any other grapes. As the grape ripens, acids convert into sugar, and you will find them sweeter.
Are Purple Grapes Acidic?
Purple grapes, also known as concord grapes, are highly acidic (pH 1.9) in nature. They have a wide range of flavors, from sweet to spicy. The tannins in the skin of the purple grapes impact the taste. As the acids in the purple grape turn into sugar with time, ripe grapes taste sweeter than unripe ones.
Are Black Grapes Acidic?
Black grapes are acidic due to additional phenolic acid and typical tartaric and malic acid. The flavonoid pigment in the skin gives black grapes their signature color. When the grape darkens in color, it’s because more antioxidants are present. This is why black grapes are more popular than any other grapes.
Are Concord Grapes Acidic?
Concord grapes are a variety of purple grapes. So, it’s obvious that they will be acidic like any other purple grapes. The acid content of the concord group is not directly connected with the acidic nature of the fruit. So don’t be surprised if you bite a sour concord grape with a higher pH value or vice versa.
Is Grape Juice Acidic?
With a pH of 3.2–4.0, grape juice is considered an acidic beverage. However, you may be concerned that the acidity in grape juice makes it dangerous to consume daily.
The stomach has a pH of 1.5–3.5, making it significantly more acidic than grape juice; however, drinking grape juice does not affect the stomach’s pH.
Plus, grapes’ vitamins, minerals, and antioxidants make them a healthier option than commercial beverages like soft drinks.
Are Grapes Good For Acid Reflux?
It may sound unlikely, but grapes are actually good for acid reflux as long as the consumption is moderate.
Fruits are among the most acidic foods we eat. Other fruits, including grapes, apples, peaches, and pears, have a slightly higher pH than citrus fruits like lemons and limes (between 3 and 4).
While most fruits and vegetables are on the acidic side of the food spectrum, studies show that they raise blood alkalinity once consumed (meaning they have the opposite effect of an acid).
Because of their low potential renal acid load (PRAL), or the amount of acid or alkali they generate in the body, fruits and vegetables are beneficial despite having a higher pH value.
Are Grapes Bad For Acid Reflux?
Rapes are actually not bad for acid reflux, and you know why.
The PRAL of acidic fruits like grapes is low (or even negative). A higher alkaline body pH can be achieved by eating foods with a negative PRAL value (which is the opposite effect of acid). Protein-rich foods (like meat, chicken, cheese, and eggs) tend to raise acid production and have a higher PRAL.
What foods can you eat to reduce acid reflux symptoms? The predictable response is “a little of each.” Regarding GERD and overall wellness, a diet rich in foods from all food groups is ideal.
Are Grapes Acidic For Teeth?
Grapes’ high acid content means they can eat away at tooth enamel. Grapes are a good source of vitamin C, but they aren’t necessary to get the vitamin C you need every day.
Cantaloupe, for instance, has a higher pH (6.13 – 6.58) and is much less acidic than many other fruits with a similar vitamin content because it contains less sugar.
Fruits like bananas, honeydew melons, and watermelons are also appropriate for this purpose.
Are Grapes Acidic Foods?
Grapes are one of the most acidic foods, with pH ranging from 1.9 to 4.
If you are not a big fan of the tangy taste, grapes are not your cup of tea. However, you will love the taste of grape wine and jams.
Grape’s acidity reduces as it ripens and acids turn into sugar.
Are Grapes Good For You: Benefits of Grapes and Grape Juices
Grapes are called a nutrition powerhouse. They are loaded with nutrients, vitamins, and antioxidants. If you can keep the consumption moderate, you can benefit from the fruit and the juice.
Grape
The Natural Medicines Comprehensive Database reports that grape plant (Vitis vinifera) parts, including fruit, seeds, skins, and leaves, are used for various medical purposes, some of which are supported by research and others of which have insufficient evidence (NMCD).
Heart Healthy
Journal of the American Dietetic Association published a systematic review of human trials that found a grape variant, grape seed extract, reduced systolic blood pressure (the pressure in the blood vessels when the heart beats), and heart rate.
Type 2 Diabetes Control
Evidence shows that consuming whole grapes can reduce the likelihood of developing type 2 diabetes.
Blueberries, grapes, and apples were found to be “significantly associated” with a reduced risk of developing the condition in a long-term study of over 190,000 healthy individuals published in August 2013 in the journal BMJ.
Anthocyanin is a flavonoid with antioxidant properties that can help keep blood sugar under control. It is found in high concentrations in blueberries, darker grapes, and apples.
Grape Juices
From the perspective of providing humans with micronutrients and minor BAS, the most crucial components of grape juice are potassium, magnesium, iron, manganese, flavonoids, and hydroxycinnamic acids.
Antioxidant Quality
The anthocyanins found in red and purple grape juices (on average, 3 mg/100 cm3) are responsible for giving grapes and grape juice their characteristic color. Roughly half of the anthocyanins in grape juice are malvidin glycosides.
Resveratrol, a stilbenoid, is also present in grape juices (on average 0.01 mg/100 cm3). It has recently attracted much attention due to its powerful antioxidant properties. Grape juice typically contains 5 mg/100 cm3 of caftaric acid and other hydroxycinnamic acids.

Side Effects of Grapes
It’s not good to gorge on your favorite fruit. Ingesting an excessive number of grapes has serious consequences due to their small size, which can be deceptive. Consuming more than a bowlful (roughly 30–40 grapes) of grapes every day can have undesirable effects.
- Diarrhea/constipation
- Allergy
- Abdominal pain
- Weight gain
Vitamin K in grapes may interfere with the effectiveness of blood-thinning medications like Coumadin and Jantoven (warfarin).
You shouldn’t cut out grapes and other vitamin K-rich foods, but you should aim to keep your daily intake consistent. If you are on blood thinner medication, discussing your diet with your doctor and any dietary supplements you take, such as grape seed extract, is important.
Conclusion
So what do you think, are grapes acidic?
Yes, grapes are acidic, but it doesn’t limit you from enjoying the sweet and spicy taste in any way. In fact, you should include this nutrient powerhouse in your daily diet to keep the acid reflux and other health issues at bay.
Whether you are worried about your heart health or blood sugar, a bowl of grapes every day or a sip in the red wine glass will energize you.