Are Onions Acidic or Basic? Avoid With Acid Reflux or Not
Medically reviewed by Christiana George Updated Date: January 1, 2026
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.
| Type of Onions | pH value |
| Onions (Green) | 6.00-7.00 |
| Onions (White) | 5.37-5.85 |
| Onions (Red) | 5.30-5.80 |
| Onions (Yellow) | 5.32-5.60 |
| Onions (pickled) | 3.70-4.60 |
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.
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Apricot Raspberry Galette, Or Look What I Made!
Under Elisabeth Prueitt’s tutelage, I feel invincible.
She’s the co-founder of Tartine Bakery in San Francisco, head pastry chef, and, purveyor of all things baked and sweet and wonderful. Along with her husband Chad Robertson, they’ve turned Tartine into something of an institution. This is a widely-acknowledged fact. Even if institutions are generally quite a bit older than the 10 years that this bakery’s been around. Anyway, I’m sure many of you savvy cooks and bakers have heard of it, so I won’t wax any more poetic except to say that the almond croissants are SO SO good.
Instead, I meant to give you a recipe for an apricot raspberry galette.
I’ve always been charmed by galettes; they’re so endearing and sweet, homely little things brimming with the fresh and organic. At the same time, I’ve always been intimidated by the idea of making the crust—tart doughs seem such fickle things. So in undertaking this recipe, I knew that I wanted to turn to Prueitt’s cookbook Tartine… she’s never led me astray, you see.
She describes galettes as “quintessentially beautiful rustic tarts… they are very satisfying to make.” I wanted to grasp satisfying! More than that, I wanted to feel the gratification that comes from sinking my teeth into something substantial. I wanted to feel the flour and butter between my fingers, build something lovely and wholesome completely out of scratch. The process of baking, of creating really, is never as palpable as when you’re getting your hands (and in my case, feet) dirty, smearing butter everywhere, flexing those arm muscles rolling and lifting and pleating. It’s a rewarding feeling.
So I took out the rolling pin—we don’t see much of it these days—and began the painstaking process of flattening frozen butter into long thin strips in flour. Which came together into something that resembled dough. Which came together into something that resembled a free-formed tart. And when it came out of the oven, I was astonished to find a galette. It came out rustic indeed. Seven-sided, lopsided, shriveled fruit and all, I loved it upon sight. Because I’d made it from scratch.
APRICOT RASPBERRY GALETTE
Fruit Galette recipe in Tartine by Elisabeth Prueitt & Chad Robertson
Makes 1 large galette or 6 mini galettes
Ingredients:
For dough:
1 cup (2 sticks) unsalted butter, very cold
1/2 cup water
3/4 tsp salt
1 cup rye flour
1-1/2 cups all-purpose flour (or use all all-purpose if you’d like)
For filling:
3 cups fruit (berries, stone fruit, sauteed apples or pears, etc.)
2 to 4 Tbsp brown or granulated sugar
Lemon juice if needed
Egg wash:
1 large egg yolk
1 Tbsp heavy cream
Granulated sugar for sprinkling
Directions:
Cut the butter into 1-inch cubes and put them in the freezer. Measure the water, dissolve the salt into it, and put it into the freezer. Chill both the butter and the water for about 10 minutes.
Measure the flour onto your work surface and spread it into a rectangle about 1/3 inch deep. Don’t worry about mixing it, as it’ll get mixed in the process. Scatter the butter cubes over the flour and toss some flour over them so they don’t stick to your rolling pin. Begin rolling. When the butter starts flattening into long, thin strips, use a bench scraper to scoop up the sides so it’s about the same size as when you started. Repeat this rolling and scraping 3 to 4 more times.
Make a well in the center and pour in the cold water. With the bench scraper, scoop the sides of the dough into the center, mixing the water and flour in a cutting motion. Keep scraping and cutting until the dough is shaggy, then shape it into a rectangle about 10 by 7 inches. Dust the top lightly with flour. Roll out the flour until it’s about half as thin, then scrape all four sides back to its original shape and reroll. Repeat this a few more times until your dough is smooth, cohesive. You should end up with a 10 by 7 inch rectangle.
Transfer the dough to a large baking sheet, cover it with plastic wrap, and chill for about 1 hour.
While the dough is chilling, prepare your fruit. Peaches can be sliced into eighths, apricots quartered.
When the dough is chilled, you can divide it into six equal parts at this point. Roll the dough into a rough circle of about 14 inches in diameter if making a single galette or 6 to 7 inches if making mini galettes. (Prueitt gives lengthy instructions on how to do this, but for the sake of not being too fussy, I won’t go into details) Transfer the circle/s to a baking sheet and chill about 10 minutes.
Fill the center of each circle with fruit, leaving a 2-inch border if making a large galette, or a 1-inch border if making small. At this point, taste the fruit to decide how much sugar you want to sprinkle on top, anywhere from 2 to 4 Tbsp on the large galette or 1 to 2 tsp on each small galette. If you want, squeeze some lemon juice on top. Fold in the sides into that classically gorgeous galette shape, making sure to seal crevices where the juice can leak out. Chill for about 10 minutes, and start preheating the oven at 375 degrees F.
At this point, Prueitt says you can store them in the fridge, unwrapped, for a few hours or wrap them airtight and store them in the freezer for up to 2 weeks. Otherwise, make your egg wash by whisking together the cream and egg yolks. Brush the egg wash on the pastry edges and sprinkle them with granulated sugar.
Bake the galettes until the crust has visibly puffed and baked to a dark brown and the fruit juices are bubbling, 45 to 60 minutes for the large galette and 40 to 50 minutes for the small. Rotate halfway through for even browning. (If baking them straight from the freezer, tack on about 10 minutes to the baking time.) Remove from the oven and serve immediately, or let it cool and serve warm or at room temperature.
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