pH of Potato — Acidic or Alkaline?

pH of Potato

The scientific name of potato is Solanum tuberosum. It is a nightshade perennial plant of the Solanaceae family. It grows as a tuberous root. A raw potato consists of around 79% water, 17% carbohydrates, and other minor nutrients.

It is the fourth largest food crop grown around the world with China being its biggest producer. A number of potato varieties are found across the globe that vary in their nutritional content.

Many of you may have doubts about whether potatoes are acidic or alkaline and their pH level. So, In this article, I will answer you and will cover its related topics.

So, are potatoes acidic? Potatoes are mildly acidic and have a pH value between 5.4 and 6.1. It is due to the presence of different types of naturally occurring acids in potatoes. These acids constitute about 0.4 – 1% of their fresh weight. Although potatoes are mildly acidic, they have an alkalizing effect on the body after consumption.

It is well known that pH value is an indicator of the acidity or alkalinity of a substance. A pH value below 7 is a property of acids while a pH value above 7 signifies an alkaline substance.

As potatoes have a pH value slightly lesser than 7, they are mildly acidic in nature.

pH scale


Which Acid is Present in Potatoes?

The pH of a substance is actually the potential of hydrogen ions in that substance.

As per the Arrhenius theory, any material that dissociates to form hydrogen ions in a solution is an acid, therefore, the high concentration of hydrogen ions in a substance is an indicator of its high acidity which means lower pH, as it is the negative log of hydrogen ion concentration.

The pH value of potatoes is around 5.4 to 6.1 which is slightly lower than 7, which is neutral pH. Hence, potatoes are only slightly acidic.

Potatoes are acidic due to the presence of a number of acids. The acids normally present in potatoes are malic acid, citric acid, phosphoric acid, oxalic acid, glutamic acid, and pyroglutamic acid.

All of these are mild acids due to which they bring down the pH of potatoes slightly below neutral. The concentration of these acids varies in different varieties of potatoes based on their geographical location, soil type, fertilizers used, etc.

This is also the reason for the different tastes, properties, and nutritional values of different potato species.

Potatoes are also a good source of carbohydrates, many essential vitamins such as vitamin C, D, and B, and also minerals like potassium, calcium, etc.

Many of the food items viz. fruits, vegetables, etc. in their natural form are acidic. However, this does not definitely mean that they will still remain acidic after entering your digestive system.

Most of them change into alkaline form once digested, although this also depends upon the method of cooking and ingredients added during the process.

Potatoes are the same that is why they are good for reducing the levels of gastric acid by absorbing extra acid from the stomach.

One such similar food item is lemon. I have written a specific article on is lemon acidic or alkaline.

Consumption of potatoes may reduce the risk of gastroesophageal reflux disease, also referred to as GERD by 42%. However, the carbohydrate content of potatoes may adversely affect the symptoms causing more acid reflux.


Are Boiled Potatoes Acidic or Alkaline?

Boiling potatoes does not have much impact on their pH which remains more or less the same.

However, it may result in depleting its nutritional value as many of the water-soluble vitamins such as vitamin C are lost during the boiling process.

Tips to boil Potatoes: How to boil potatoes perfectly

The pH value of boiled potatoes also gets affected due to the acidity or alkalinity of water they are boiled in and if salt or other spices were added during the boiling process.

If the water used for boiling is acidic it may result in lowering the pH value making the potatoes more acidic. Also, boiling potatoes in acidic water make them firmer while using alkaline water make them softer in texture.

Further, using salt or spices while boiling are after may intensify the acid content of potatoes.


Are Sweet Potatoes Acidic?

Sweet potatoes are recognized in the scientific community by the name Ipomoea batatas.

They are also a type of tuberous roots and belong to the family Convolvulaceae. They are distantly related to the common potatoes as they are both included under the order Solanales of Kingdom Plantae. They are mostly used for eating and sometimes also grown for ornamental purposes.

Sweet potato - Wikipedia

The pH value of sweet potatoes lies between 5.3 and 5.9. This means that they are also mildly acidic similar to normal potatoes.

Also, like normal potatoes, they tend to turn alkaline as they get digested. Due to this property, they also make a good fit for an alkaline diet.

Also, they are a good source of various vitamins such as vitamin A and vitamin C, and minerals like manganese, potassium, phosphorous, etc.

However, frying sweet potatoes changes their pH making them quite acidic and not suitable to be consumed as a part of an alkaline diet.


Are Baked Potatoes Acidic?

Baking potatoes is the most efficient way of saving their nutritional contents. This is especially true when they are baked along with their skin.

We all know that cooking any food takes away some amount of nutrients out of it. However, when baking is done at optimized temperatures it results in minimal nutrient loss.

Best Microwave Baked Potato Recipe - How To Make Microwave Baked Potato

The pH value of baked potatoes also remains more or less similar to raw potatoes i.e. they are mildly acidic.

Rather baked potatoes are sometimes classified as alkaline. However, this depends upon how you bake potatoes.

Adding a lot of spices, butter, or salt would reduce the pH value making them acidic. Therefore, to have a normal alkaline pH, potatoes must be baked alone without adding any other ingredient.

Also, just like sweet potatoes, potatoes also turn acidic when fried. Actually, frying any kind of food turns it acidic and lowers the nutritional content making them unsuitable to be consumed for a healthy diet.


Are Mashed Potatoes Acidic?

During mashing, potatoes are crushed to a soft semi-solid mass. This is done using hot water or after slightly boiling the potatoes which makes them softer. This process does not cause much change in the pH of the potatoes.

Mashed potato - Wikipedia

However, mashed potatoes are usually prepared for serving by adding a large amount of butter, salt, or spices that reduce their pH making them more acidic.

Therefore, mashed potatoes are not considered suitable to be included in the diet of people suffering from gastritis as their consumption may further enhance the symptoms of GERD by reacting with the stomach acid and aggravating its effects.


Types of Potatoes

There are over 5000 varieties of potatoes known worldwide however, not all of them are edible. A few varieties of potatoes along with some of their properties are described below.

Please note that these varieties may further be divided into more sub-categories known by different names around the globe.

Russet Potatoes: They are large, brown-skinned potatoes that are specially used in restaurants for making French fries due to their long size.

They have high starch content and a lower moisture value. They are also recognized by the name Idaho potatoes.

Russet potato - Wikipedia

Red Potatoes: They are red in color, naturally gluten-free, and loaded with many other qualities. They help balance blood pressure levels as they are a good source of potassium.

They are also a great source of vitamin C due to which they work as immunity boosters.

Fresh Red Potato at Rs 9/kilogram | रेड पोटैटो - Rajendra Kumar Rakhabchand, Indore | ID: 14090301491

Yellow Potatoes: As the name indicates they are slightly yellow in color.

They are a good source of carbohydrates. They are also rich in fiber, vitamins such as vitamin C, B, as well as minerals like calcium, potassium, etc.

Best Yellow Potato Varieties & Yellow Potato Products Southern California

White Potatoes: They are also known as Irish potatoes. They are a good source of potassium and calcium, and also contain a large amount of soluble and insoluble fiber.

White potatoes : Substitutes, Ingredients, Equivalents - GourmetSleuth

Fingerlings: These are the variety of potato that naturally grows into a finger-like shape. They are small and stubby and naturally small in size and narrow in appearance.

They have a waxy texture and are low in starch content.

Fingerling Potatoes - Ingredient - FineCooking

Below is the video attached regarding different types of potatoes and the differences among them.




The pH value of potatoes lies between 5.6 and 6.1 indicating that they are slightly acidic in nature. 0.4 – 1% of the fresh weight of potatoes is made of acids.

Potatoes majorly consist of malic acid, citric acid, phosphoric acid, oxalic acid, glutamic acid, and pyroglutamic acid.

Boiling does not impact the pH of potatoes. However, boiling in acidic water and adding salt and spices may reduce the pH further.

Sweet potatoes are also slightly acidic and their pH value lies between 5.3 and 5.9.

Baking also does not have much effect on the acidity of potatoes. It is rather a healthier way of cooking conserving most nutrients.

Mashed potatoes are prepared by adding a large amount of butter, salt, or other spices which enhance their acidity.

You must read a few similar articles mentioned below.

pH of Tomato

pH of Banana

pH of Honey

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