How to Caramelize Onions

LAST UPDATED: May 04, 2021 | PUBLISHED: Mar 09, 2021 | By:

Learn how to caramelize onions in just a few minutes, with very little effort! They are the perfect addition to dips, burgers, tacos and more!

Caramelized onions are easy to make with just two ingredients, and these onions are a great addition to so many recipes!

up close shot of caramelized onions

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It seems like such a simple thing, right? Well, I’m often asked how to caramelize onions and it’s one of those things I just do, without thinking about.

Kind of like how my grandma baked – a little of this, a pinch of that. I realized when trying to explain to my sister that I should share how to caramelize onions in a little more detail.

I love how simple and easy it is to make these onions, the finished result are slightly sweet onions that have retained their juices. I find the best recipes that you use time and time again are often the simplest, and this makes an appearance on a weekly basis in our house!

You just need two basic ingredients to make these melt-in-your-mouth onions!

A silver saute pan on a marble surface, filled with caramelized onions

Why You’ll Love These Onions

  • So easy
  • Pantry ingredients
  • Perfect topping for so many recipes
  • Keep well in fridge or freezer

Ingredients for Caramelized Onions

  • Onions – White, yellow or red onions all caramelize beautifully. Shallots also caramelize well.
  • Oil – Vegetable oil, olive oil or butter
A marble surface topped with two whole yellow onions and two tabs of butter.

Variations

  • Brown Sugar – Add in a tablespoon of brown sugar.
  • Balsamic Vinegar – Deglaze with balsamic for added color and flavor.
  • Cayenne – Add a 1/2 teaspoon cayenne spice it up.
  • Oil – Instead of butter, caramelize your onions in any type of oil.

How to Caramelize Onions

  1. Slice Onions – I generally use two onions because one is never enough. It may seem like a lot when they are raw, but once they caramelize, they reduce significantly in size. 
  2. Sauté – Place them in your pan over medium heat. I frequently use my cast iron skillet, but any will do. Allow the butter to melt or the oil to heat, then toss using my secret weapon – tongs. Allow to simmer for 10 minutes. up close shot of caramelized onions, tongs pulling up a few.
  3. Caramelize – Toss the onions and caramelize for another 10 minutes, and up to half an hour longer. Depending on how caramelized you’d like them to be, you can cook them on low for up to one hour in total.
up close shot of caramelized onions, tongs pulling up a few.

Serving Suggestions

There’s rarely a week when I don’t have onions cooking to make something fabulous! They add an amazing flavor to liven up any meal!

Scaling up, down or substituting? You’ll love this printable Measurement Conversion Chart!

Tips

  • Oil – Use just one tablespoon of oil or butter per onion, or the sautéed onions can become too greasy. Be sure to put a lid on the sauté pan – this speeds up the cooking and helps the onions retain their moisture.
  • Make them Vegan – To make the onions vegan, use a plant based oil or butter.
  • Darker – to make your onions darker and more rich-looking (as in the photo in the glass container below) add a tablespoon of balsamic or brown sugar.

How to Store

  • Room Temperature – Caramelized onions can be kept at room temperature for up to two hours while serving.
  • Refrigerate – Once the onions are cooked, let them cool to room temperature and place them in an airtight container in the fridge and they will keep up to one week. You can then use them as is in recipes, or you can reheat them gently on the stovetop to serve.
  • Freeze – Store in airtight container or freezer bag up to three months. Double wrap to avoid onion odor seeping into other frozen goods.
Cooked onions in a glass jar
Do caramelized onions have sugar?

Onions are sweet by nature prior to cooking, and caramelizing is the process of drawing those sugars out slowly as they cook.

What is the difference between caramelized onions and sauteed onions?

Browning is a much quicker process, and while it works to soften the onions, it doesn’t bring out the same sweet caramelized flavor. Caramelizing takes anywhere from 20 minutes to an hour, depending on how low and slow you cook your onions.

Why are my onions not caramelizing?

Don’t pack too many in the pan! This creates too much steam and won’t allow them to break down and brown, which brings the caramelized sugars to the surface.

up close shot of caramelized onions

Dietary Considerations

  • Gluten Free
  • Dairy Free
  • Nut Free

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up close shot of caramelized onions, tongs pulling up a few.

How to Caramelize Onions

Author: Julie Blanner
Learn how to caramelize onions in just a few minutes with very little effort for the perfect addition to dips, burgers, tacos and more!
5 from 1 vote
Prep Time 5 mins
Cook Time 25 mins
Total Time 30 mins
Course Condiment
Cuisine American
Servings 8
Calories 31 kcal

Ingredients
  

  • 2 large yellow onions
  • 2 tablespoons oil

Instructions
 

  • Slice onions and put them in a pan over medium heat.
  • Drizzle with vegetable oil, then toss to coat. Cover the onions with a lid and cook for 10 minutes.
  • Stir the onions, replace the lid and let them continue to caramelize for another 10 minutes.
  • Stir and continue cooking for another 5 minutes, when golden brown and soft.

Video

Notes

Tips

  • Oil – Don’t use more than 2 tablespoons of oil or butter, or the sautéed onions can become too greasy. Be sure to put a lid on the sauté pan – this speeds up the cooking and helps the onions retain their moisture.
  • Make them Vegan – To make the onions vegan, use a plant based oil or butter.
  • Depending on how caramelized you’d like them to be, you can cook your onions on low heat for up to one hour in total.

To Store

  • Refrigerate – Once the onions are cooked, let them cool to room temperature and place them in an airtight container in the fridge and they will keep up to 7 days. You can then use them as is in recipes, or you can reheat them gently on the stovetop to serve.
  • Freeze – Store in airtight container or freezer bag up to 3 months. Double wrap to avoid onion odor seeping into other frozen goods.

Nutrition

Calories:31kcalFat:4gSaturated Fat:1g
5 from 1 vote
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