Potato pH: Is it Acidic or Alkaline?

Solanum tuberosum is the scientific name for potato. It is a perennial nightshade plant in the Solanaceae family. It takes the form of a tuberous root. A raw potato is made up of 79 percent water, 17 percent carbs, and a few other minor nutrients.

It is the world’s fourth largest food crop, with China producing the majority of it. Potatoes come in a variety of nutritional profiles and can be found all over the world.

Many of you may be unsure whether potatoes are acidic or alkaline, or what pH level they have. So, in this essay, I’ll respond to your question and discuss similar issues.

So, how acidic are potatoes? Potatoes are moderately acidic, with a pH range of 5.4 to 6.1. It’s because potatoes contain several distinct types of naturally occurring acids. These acids make up roughly 0.4–1% of their total fresh weight. Although potatoes are somewhat acidic, when consumed, they have an alkalizing impact on the body.

The pH value is a well-known indicator of a substance’s acidity or alkalinity. A pH number less than 7 indicates an acidic substance, while a pH value more than 7 indicates an alkaline substance.

Potatoes are mildly acidic in nature since their pH value is little less than 7.

What Acid Can You Find in Potatoes?

The potential of hydrogen ions in a substance is represented by its pH.

According to the Arrhenius theory, any material that dissociates to create hydrogen ions in a solution is an acid. As the negative log of hydrogen ion concentration, a high concentration of hydrogen ions in a substance indicates a high acidity, which means a lower pH.

Potatoes have a pH range of 5.4 to 6.1, which is somewhat lower than the neutral pH of 7. As a result, potatoes are only mildly acidic.

Because of the presence of a variety of acids, potatoes are acidic. Malic acid, citric acid, phosphoric acid, oxalic acid, glutamic acid, and pyroglutamic acid are the acids found in potatoes.

All of them are weak acids that cause the pH of potatoes to fall slightly below neutral. The content of these acids varies among potato varieties depending on their geographical location, soil type, fertiliser application, and other factors.

This is also why different potato species have diverse tastes, characteristics, and nutritional qualities.

Potatoes are also high in carbs, as well as numerous critical vitamins including vitamin C, D, and B, as well as minerals like potassium and calcium.

Many foods, such as fruits and vegetables, are acidic in their natural state. However, this does not guarantee that they will remain acidic once they have passed through your digestive system.

When they are digested, the majority of them become alkaline, albeit this is dependent on the type of cooking and the components added during the process.

Potatoes are the same, which is why they can help lower gastric acid levels by absorbing excess acid from the stomach.

Lemon is an example of a related food item. I’ve written an article about whether lemons are acidic or alkaline.

Potato consumption may lower the risk of gastroesophageal reflux disease, popularly known as GERD, by 42 percent. Potatoes, on the other hand, have a high carbohydrate content, which may exacerbate acid reflux symptoms.

Are boiled potatoes alkaline or acidic?

Boiling potatoes has little effect on their pH, which remains rather constant.

However, because many water-soluble vitamins, including as vitamin C, are lost during the boiling process, it may lose nutritional value.

The acidity or alkalinity of the water in which the potatoes are boiled, as well as whether salt or other spices were added during the boiling process, alter the pH of the potatoes.

If the water used for boiling is acidic, the pH of the potatoes may be lowered, making them more acidic. In addition, boiling potatoes in acidic water makes them tougher, but boiling them in alkaline water makes them softer.

Furthermore, adding salt or spices to the boiling water might increase the acidity of the potatoes.

Is it true that sweet potatoes are acidic?

Sweet potatoes are referred to as Ipomoea batatas in the scientific community.

They are a form of tuberous root that belongs to the Convolvulaceae family. They are distantly related to common potatoes, as they both belong to the Kingdom Plantae’s Solanales order. They’re usually cultivated for food, although they’re also sometimes planted for ornamental purposes.

Sweet potatoes have a pH of between 5.3 and 5.9. This means they’re moderately acidic, much as regular potatoes.

They also tend to become alkaline as they are digested, just like regular potatoes. They’re also a fantastic fit for an alkaline diet because of this feature.

They’re also a good source of vitamins like vitamin A and vitamin C, as well as minerals like manganese, potassium, and phosphorus.

Sweet potatoes, on the other hand, lose their alkalinity when they are fried, making them acidic and unsuitable for an alkaline diet.

Is it true that baked potatoes are acidic?

Baking potatoes is the best way to preserve their nutritional value. This is especially true when their skin is baked with them.

We all know that cooking removes part of the nutrients from any food. When baking is done at the right temperature, however, nutritional loss is low.

Baked potatoes have a pH value that is similar to that of raw potatoes, i.e. they are mildly acidic.

Baked potatoes, on the other hand, are occasionally characterised as alkaline. This, however, is dependent on how the potatoes are baked.

When you add a lot of spices, butter, or salt to a dish, the pH value drops, making it acidic. As a result, potatoes must be roasted alone without any other ingredients to maintain a normal alkaline pH.

Potatoes, like sweet potatoes, become acidic when they are fried. In fact, frying any type of food makes it acidic and reduces the nutritious value, making it unfit for a balanced diet.

Is it true that mashed potatoes are acidic?

Potatoes are smashed into a soft semi-solid mass during mashing. This can be done with hot water or after the potatoes have been partially boiled to soften them. The pH of the potatoes does not alter considerably as a result of this treatment.

However, mashed potatoes are typically prepared for serving by adding a lot of butter, salt, or spices, all of which lower the pH of the potatoes and make them more acidic.

As a result, mashed potatoes should not be included in the diet of those who have gastritis, as their consumption may exacerbate the symptoms of GERD by interacting with stomach acid and increasing its effects.

Potatoes Come in a Variety of Shapes and Sizes

Potatoes come in over 5000 types around the world, but not all of them are edible. A few potato types are listed here, along with some of their characteristics.

Please keep in mind that these variations can be further separated into sub-categories with distinct names all around the world.

Russet potatoes are huge, brown-skinned potatoes that, due to their length, are commonly used in restaurants to make French fries.

They contain a lot of starch and have a low moisture content. Idaho potatoes are another name for these potatoes.

Red potatoes have a bright red colour, are naturally gluten-free, and have a long list of other benefits. They are a wonderful source of potassium, which helps to keep blood pressure in check.

They are also high in vitamin C, which helps to promote immunity.

Yellow Potatoes are slightly yellow in colour, as the name suggests.

Carbohydrates are abundant in them. They’re also high in fibre, vitamins such as C and B, and minerals such as calcium and potassium.

White potatoes, commonly known as Irish potatoes, are a type of potato. They’re high in potassium and calcium, and they’re also high in both soluble and insoluble fibre.

Fingerlings are a potato type that grows naturally into a finger-like form. They’re short and stubby, with a naturally small and thin appearance.

They have a waxy feel and contain little starch.

The video below explains the various types of potatoes and the differences between them.


Potatoes have a pH range of 5.6 to 6.1, indicating that they are mildly acidic in nature. Acids account for 0.4–1% of the fresh weight of potatoes.

Malic acid, citric acid, phosphoric acid, oxalic acid, glutamic acid, and pyroglutamic acid are the most common acids found in potatoes.

The pH of potatoes is unaffected by boiling. Boiling in acidic water and adding salt and spices, on the other hand, may lower the pH even further.

Sweet potatoes are slightly acidic as well, with a pH range of 5.3 to 5.9.

The acidity of potatoes is unaffected by baking as well. It is a healthier manner of cooking because the majority of nutrients are preserved.

Mashed potatoes are made with a lot of butter, salt, or other seasonings that increase the acidity of the potatoes.

Read more: Geometry, Hybridization, and Polarity of CHCl3 Lewis Structure

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.


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