Onions are part of almost everyone’s vegetable basket in the kitchen. They are added to different cuisines and salads to enhance the aroma, flavor, and quality. You read a recipe for any delicious-looking dish and will most likely see onion as an ingredient. But very few people know about the nature of this vegetable. Are onions acidic, basic, or neutral? 

Onions are acidic in every form and variety. Whether raw, cut, red, yellow, Green, or white, all onions are acidic in nature. Because onions pH level is 5 to 5.8 depending on cooked or raw onions. As onions pH is less than 7, so onions are acidic.

It is important to know why onions are acidic and how is it safe to consume them. You might wonder, is the acidity of onions strong enough to induce any negative effect on health? If you want to know the answers, then keep reading. 

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How Acidic Are Onions?

Onions are not considered super acidic like lemon or lime. But they are also not considered close to neutral either. 

Thus, the acidity of onions is neither considered extreme nor slight. 

To know the acidity status clearly, you can check out the onion pH value.

What is the pH of Onions?

The Onion pH level is between 5 to 5.8, depending upon varieties and onion forms. I am describing their details later in this article.

Let me tell you a bit about the pH scale for those who are unfamiliar. If the value of anything is below 7, it is considered acidic. If it is 7, it is considered neutral, while above 7 pH value things are considered basic or alkaline.

Since an onion’s pH is below 7, it is termed acidic food. Want to know the reason behind this low pH?

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Why Are Onions Acidic?

Have you ever wondered, why are onions acidic food?

Onions are acidic due to the high amount of Ascorbic acid (Vitamin C), Pantothenic acid (Vitamin B5), and sulfur.

Although the two nutrients and sulfur are super important for us, they are also the reason why Onions taste a bit sour (kind of like Acid) and have low pH.

This sulfur content is also the reason why we cry during the cutting of onions.

Are Onions Bad for Acid Reflux?

After knowing about their acidic status, you might now be wondering- are onions good for acid reflux or not?

Onions are considered bad for those who have Acid Reflux.

One reason is the acidic nature of this vegetable. But the biggest reason is that Onions are rich in FODMAPS (Fermentable oligosaccharides, disaccharides, monosaccharides, and Polyols).

These carbs are non-digestible, so the stomach finds it hard to deal with them. Hence, the stomach releases more acid to break them but ends up worsening Acid reflux.

Are Onions Good for Heartburn?

Onions (especially Raw) are considered one of the leading causes of heartburn.

The reason is how they prompt the stomach to release acid. Actually, heartburn is also the main symptom of Acid reflux.

A study was conducted in which one group of people were given “onion-less burgers” while the other group was lavished with “Burgers with onions” It was found that those who ate burgers with onions had heartburn problems frequently.

Is Every Onion Bad for Acid Reflux?

There are more than a dozen varieties of onions we have today.

The most famous ones we use in the kitchen are Red, Green, and Yellow/Brown. Want to know which onion is less acidic? Then keep on reading!

Are Red Onions Acidic?

People often ask, are red onions acidic or alkaline? Red Onion pH level is between 5.7 to 5.8. So, it is acidic.

The question now is- are red onions bad for acid reflux?

Red onions are bad for acid reflux if you consume them in large quantities.

Adding a small amount won’t cause or worsen the acid reflux. You have to be super sensitive to acidic foods to feel this negative effect of Red onions.

Since it is not easy to digest red onions, eating them more can cause stomach problems and also Acid reflux.

Are Green Onions Acidic?

After reading about red onions, you might now be wondering, are green onions acidic or alkaline?

Green onion or spring onion is not acidic. In fact, it is one of the least acidic onion varieties.

Some people even say it’s Alkaline.

The green onion pH level is around 6.0 to 7.0, depending upon how you cook it. Generally, the pH level of Green onions stays around 7.2.

Are green onions bad for acid reflux?

Green onions are still not desirable to eat for those with Acid reflux.

The FODMAPS in them do not digest, so the stomach deals with them by releasing more acid. Hence, the Acid reflux is worsened.

But you have to consume green onions in large quantities or daily to feel this impact.

Are Yellow Onions Acidic?

Around 90% of the onions stored in the USA are Yellow onions. They are also known as brown onions in some parts.

Yellow onions are also acidic, with a pH level of 5.6. Thus, they are not good for those who are already feeling the symptoms of Acid reflux and heartburn.

However, cooking them reduces acidity levels. So, adding a little amount of it won’t do any harm.

Are Cooked Onions Acidic?

Wondering, are cooked onions acidic or alkaline? Just like Raw onions, cooked onions are acidic. 

However, it is also true that cooking onions reduce their acidity levels. The reason is that most of the sulfur in onions is converted into sulfide.

Another question that arises here is, are cooked onions ok for acid reflux?

 Cooked onions are less likely to cause any rise in stomach acidity levels. It is because cooked onions are easier to digest than raw and also have a high pH. 

Cooked onion pH level is between 5.5 to 6, depending upon the variety (excluding Green onion). Cooked Green onion pH is 7.5.

Frequently Asked Questions (FAQS)

Are Caramelized Onions Acidic?

Caramelized onions are made by adding sugar. This sugar content raises the pH levels, and the caramelized onions get close to neutral. So, it is mildly acidic on a pH scale. However, since the sugar content is more in it, the stomach cannot digest it smoothly. Thus, more acid is secreted, which worsens acid reflux.

Are Pickled Onions Acidic?

Pickled onions are more acidic than raw onions. The reason is the vinegar which is used during the pickling process. So, don’t overeat them. Plus, only consume pickled onions once in a while to stay healthy.

Are Onions Good for Ulcers?

Onions contain flavonoids that can treat Ulcers. However, make sure you consume it in low amounts, as consuming them more can cause acid reflux, which further makes the Ulcer painful. In addition, onions have also been shown to improve Gastritis.

Bottom Line

In a nutshell, everyone should know about the nature of the fruits and vegetables they consume. Onion is one vegetable that people add to many meals and salads.

So, are onions acidic or basic?

Onions are acidic, with a pH level between 5 to 5.8, depending upon variety.

However, one variety called Green onion has a pH level between 6.0 to 7.0

Cooking the onion reduces the acidity levels slightly as the sulfur content decreases. However, it is still strong enough to cause acid reflux, heartburn, and GERD.

That is why I suggest you consume onions moderately to live a healthy life.