Caramelized Onions

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Jammy, sweet caramelized onions can transform the simplest dishes, like grilled cheese and burgers, into cheffy delights.

caramelized onions in bowl

Caramelized onions are jammy, sweet wonders that have the power to elevate even the simplest of dishes—think of your everyday grilled cheese or a steakhouse burger—into something truly “cheffy.” Starting with what seems like an enormous mountain of onions, you’ll be amazed to watch as they cook down to just 1½ cups of deeply flavored, richly browned goodness. Patience is absolutely key here. The caramelization process can take anywhere from 45 minutes to over an hour, largely depending on the size of your pan—the bigger the pan, the quicker the onions will caramelize.

Consider this a leisurely weekend cooking project that will fill your home with the most heavenly aroma. Once done, caramelized onions can be conveniently stored in the fridge for up to two weeks or frozen for up to 3 months, ready to be used whenever needed.

Ways To Use Caramelized Onions

What You’ll Need To Make Caramelized Onions

ingredients to make caramelized onions

Find the printable recipe with specific measurements below.

  • Butter and Vegetable Oil: This combination provides the best of both worlds. Butter offers rich flavor, while the oil prevents the butter from burning.
  • Yellow or Vidalia Onions: Thinly slicing the onions ensures they cook evenly and caramelize properly.
  • Salt and Freshly Ground Black Pepper: Enhances the flavor of the onions and helps in drawing out moisture, aiding in the caramelization process,
  • Freshly Ground Black Pepper: Adds a subtle warmth.
  • Sugar: A small amount enhances the onions’ natural sweetness.
  • Water: As the onions cook and begin to stick to the pan, a bit of water should be added to deglaze the pan. This helps in lifting the flavorful browned bits (fond) from the bottom of the pan and incorporates them back into the onions, enriching their flavor.

Step-by-Step Instructions

In a large, heavy-bottomed skillet, melt the butter with the oil over medium-high heat. 

melting butter with oil in skillet

Add onions to the skillet and season with salt, pepper, and sugar.

onions added to skillet

Cook, uncovered, stirring frequently with a wooden spoon, until the onions are slightly softened, 4 to 5 minutes.

slightly softened onions

Reduce the heat to medium and continue cooking, uncovered and stirring occasionally, until the onions are a rich golden brown color. 

showing the onions with a little more golden color

This process can take anywhere from 45 to 75 minutes. In the beginning, you will only need to stir the onions occasionally. As the onions cook down and begin to brown, you will need to stir them more frequently, scraping the fond (the brown particles) from the bottom of the pan.

deglazing the pan with a bit of water

Towards the end of the caramelization process, the fond will start to stick to the pan, so you will need to occasionally deglaze the pan with a few tablespoons of water, scraping up the fond with a wooden spoon, to prevent burning and promote even caramelization.

deglazing golden brown onions in skillet

Repeat the deglazing process with the water as needed until caramelization is achieved. 

finished caramelized onions in skillet

Once the onions have achieved the rich golden brown color, remove them from the skillet, let cool, and store in a covered container in the refrigerator. The onions will keep in a covered container in the fridge for up to 2 weeks, or they can be frozen for up to 3 months. If freezing, you can divide them into small containers or freezer bags to thaw and use as needed.

How long do caramelized onions keep? How should I store them?

Caramelized onions will keep in a covered container in the fridge for up to 2 weeks, or they can be frozen for up to 3 months. If freezing, you can divide them into small containers or freezer bags to thaw and use as needed.

What type of onion is best for caramelizing?

While you can caramelize any type of onion, yellow onions are ideal for their balance of sweet and savory flavors. Sweet onions, like Vidalia or Walla Walla, can also be used and will result in a slightly sweeter finished product. Feel free to use a mix for a more nuanced taste.

caramelized onions in bowl

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Caramelized Onions

Jammy, sweet caramelized onions can transform the simplest dishes, like grilled cheese and burgers, into cheffy delights.

Servings: 1½ cups
Prep Time: 15 Minutes
Cook Time: 1 Hour
Total Time: 1 Hour 15 Minutes

Ingredients

  • 4 tablespoons unsalted butter
  • 1 tablespoon vegetable oil
  • 3 pounds yellow or Vidalia onions (or a combination), halved and thinly sliced
  • ¾ teaspoon salt
  • ½ teaspoon freshly ground black pepper
  • ¾ teaspoon sugar
  • About 1 cup water, as needed

Instructions

  1. In a large, heavy-bottomed skillet, melt the butter with the oil over medium-high heat. Add the onions, salt, pepper, and sugar. Cook, uncovered, stirring frequently with a wooden spoon, until the onions are slightly softened, 4 to 5 minutes.
  2. Reduce the heat to medium and continue cooking, uncovered and stirring occasionally, until the onions are a rich golden brown color. This process can take anywhere from 45 to 75 minutes. In the beginning, you will only need to stir the onions occasionally. However, as the onions cook down and begin to brown, you will need to stir them more frequently, scraping the fond (the brown particles) from the bottom of the pan. Towards the end of the caramelization process, the fond will start to stick to the pan, so you will need to occasionally deglaze the pan with a few tablespoons of water, scraping up the fond with a wooden spoon, to prevent burning and promote even caramelization. Repeat the deglazing process with the water as needed until caramelization is achieved. Once the onions have achieved the rich golden brown color, remove them from the skillet, let cool, and store in a covered container in the refrigerator.
  3. Make-Ahead/Freezing Instructions: The onions will keep in a covered container in the fridge for up to 2 weeks, or they can be frozen for up to 3 months. If freezing, you can divide them into small containers or freezer bags to thaw and use as needed.

Nutrition Information

Powered by Edamam

  • Per serving (8 servings)
  • Serving size: 3 tablespoons
  • Calories: 123
  • Fat: 8 g
  • Saturated fat: 4 g
  • Carbohydrates: 13 g
  • Sugar: 9 g
  • Fiber: 2 g
  • Protein: 1 g
  • Sodium: 233 mg
  • Cholesterol: 15 mg

This website is written and produced for informational purposes only. I am not a certified nutritionist and the nutritional data on this site has not been evaluated or approved by a nutritionist or the Food and Drug Administration. Nutritional information is offered as a courtesy and should not be construed as a guarantee. The data is calculated through an online nutritional calculator, Edamam.com. Although I do my best to provide accurate nutritional information, these figures should be considered estimates only. Varying factors such as product types or brands purchased, natural fluctuations in fresh produce, and the way ingredients are processed change the effective nutritional information in any given recipe. Furthermore, different online calculators provide different results depending on their own nutrition fact sources and algorithms. To obtain the most accurate nutritional information in a given recipe, you should calculate the nutritional information with the actual ingredients used in your recipe, using your preferred nutrition calculator.

Gluten-Free Adaptable Note

To the best of my knowledge, all of the ingredients used in this recipe are gluten-free or widely available in gluten-free versions. There is hidden gluten in many foods; if you're following a gluten-free diet or cooking for someone with gluten allergies, always read the labels of your ingredients to verify that they are gluten-free.

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Comments

  • My second attempt at making caramelized onions (the first attempt was a different recipe and was not really successful). Thank you for the detailed instructions and I will be using your recipe from now on. I was making this for guests and some are vegans, so used only 4 Tbsps. oil which worked really well for me (no idea why I didn’t use 5 Tbsps. or just substitute vegan margarine for the butter!) It helped that I had other tasks which kept me in the kitchen, and it was easy to periodically stir the onions.

    • — Ty on March 13, 2024
    • Reply
  • Thank you, thank you for this! I’ve struggled to carmelize onions just right and had no idea about adding a little water at a time. I can hardly wait to try again.

    • — LoisL on January 22, 2024
    • Reply

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