Caramelized Onions

Learn how to make caramelized onions perfectly every time! Rich, sweet, and deeply golden brown, they add complexity to pastas, soups, and more.

how to caramelize onions

A few weeks back, I was making caramelized onions for this French onion dip, and Jack wandered into the kitchen for lunch. Usually, after he makes himself a sandwich, he heads straight back to his office, but that day, he lingered in the kitchen. “I should go work,” he said, “But it smells so good in here.” Like roasted garlic, caramelized onions are one of those magical, powerhouse ingredients that can amp up the flavor in almost anything – dips, pastas, soups, you name it. They’re rich, silky smooth, and sweet, and, as Jack can attest, they smell fantastic too.

Luckily, caramelized onions are easy to make. BUT making them does take time. Don’t try to rush the process on a weeknight, when you’re looking for a quick, pantry-friendly topping for a pizza or veggie burger. Simply put, caramelized onions aren’t quick. It takes at least 45 minutes (and often over an hour) over low heat for the natural sugars in the onions to caramelize. Still, the time is totally worth it. Packed with irresistible umami flavor, caramelized onions add complexity to all sorts of savory dishes. If you like cooking, knowing how to caramelize onions is a must.

Yellow onions and olive oil

Caramelized Onions Recipe Tips

  • Make the full recipe. If you’re going to spend an hour or so making caramelized onions, you might as well make a lot of them! Stored in an airtight container in the fridge, they’ll keep for a week. You can also freeze them for up to two months. I like to freeze caramelized onions in ice cube trays. That way, I can easily thaw enough for a single dish and save the rest for another use.
  • Choose the right pan. I love non-stick pans for making pancakes and eggs, but they’re not the best pick for caramelized onions. Instead, I recommend using a cast-iron skillet. As the onions cook, a delicious fond will develop on the bottom of the pan. If you scrape it up and stir it into the onions, it will make their flavor even richer. Pan size also matters. It should be large and wide in order to allow moisture to evaporate as the onions cook. For 4 onions, you’ll need a 12-inch or larger skillet. For 3 onions, a 10-inch skillet works well.
  • Turn up the heat at the end. For most of the cooking process, the heat should be low or medium-low to prevent the onions from burning before they have a chance to soften and caramelize. However, once they’re brown and tender, I like to turn the heat up to medium, stirring constantly and scraping up the browned bits from the bottom of the pan, to get a little extra caramelization before I take them off the heat.

Thinly sliced onions on a cutting board

How to Caramelize Onions

My method for how to caramelize onions takes time, but otherwise, it’s really simple. Here’s how it goes:

First, slice the onions. Aim for the slices to be as even as possible so that they cook at the same rate. Before you add them to the pan, separate the onion layers.

Sliced onions in a cast iron skillet

Next, sauté! Heat olive oil (I use 2 tablespoons for 4 onions) in a large cast-iron skillet over medium heat. Add the thinly sliced onions and cook for 5 minutes, stirring frequently, until the onions soften.

Sautéed onions

Once all the onions have softened, reduce the heat to medium-low and continue to cook, stirring every few minutes. If the onions start to burn or stick to the bottom of the pan, reduce the heat to low. You could also add a splash of water if the pan starts to dry out.

How to caramelize onions

It will take 50 to 80 minutes for the onions to get deeply brown, soft, and caramelized. The exact timing will depend on the size of your pan, the size of your onions, and the heat of your stove.

caramelized onions

Serving Suggestions

When your caramelized onions look like the ones in the photo above, they’re ready to eat! You’ll find all kinds of ways to use them, but here are a few of my favorites to get you started:

How do you like to use caramelized onions? Let me know in the comments!

Get This Recipe In Your Inbox
Share your email, and we'll send it straight to your inbox. Plus, enjoy daily doses of recipe inspiration as a bonus!

Caramelized Onions

rate this recipe:
5 from 41 votes
Prep Time: 5 minutes
Cook Time: 1 hour
Serves 8
Learn how to caramelize onions perfectly every time! Rich, sweet, and deeply golden brown, they're delicious in soups, dips, pastas, and more.



  • Heat the oil in a 12-inch cast iron skillet over medium heat. Add the onions and sauté for 5 minutes or until starting to soften.
  • Add the salt, reduce the heat to medium low and cook for 50 to 80 minutes, stirring every few minutes, or until the onions are very soft, golden brown, and caramelized. The timing will depend on the size of your onions and the heat of your stove.
  • If at any point the onions start to stick to the bottom of the pan, reduce the heat to low. If the onions aren’t deeply brown after 50 minutes and you’d like to speed things up, you can turn the heat higher to get more caramelization. Stir continuously to prevent burning.


Note: this recipe can be made in a 10-inch skillet with 3 onions and 1½ tablespoons of oil.


Leave a comment:

Your email address will not be published. Required fields are marked *

Rate this recipe (after making it)

  1. pete

    course grated onions caramelized added to ground meat and milk soaked bread crumbs makes a wonderful meatloaf

  2. Jill

    I was just checking recipes to see if it was lid on for the first part; no. But so good to see a proper slow cook with no sugar. The onions are so sweet when cooked low and slow why would anyone add sugar?

    • Jeanine Donofrio

      Ha, I agree, they’re very sweet, no sugar necessary 🙂

  3. Shari

    5 stars
    I use them in lots of ways, but my favorite is in an appetizer paired with bacon and feta in puff pastry (cooked in mini muffin tins).

  4. Jay

    5 stars
    I love to caramelize onions and then load in yellow squash, some butter into the same skillet and let them get tender. Delish!

    • Kj

      5 stars
      Yummm…I make these for an onion gravy for my bangers and mash😋

      • Phoebe Moore (L&L Recipe Developer)

        So glad you loved them!

  5. Ellen

    A question, How do you slice the onions to keep them from falling apart and uniform?
    Thank you,

    • Jeannine

      5 stars
      Ellen, I use a mandoline slicer to create thin rings. It’s so easy and fast! It creates the perfect size slices for this recipe and takes literally 30 seconds per onion. At most. 🙂

  6. Jackie O

    5 stars
    These are absolutely delicious! I love serving these when we have kielbasa and pierogies. I love finding new ways to incorporate them into any meal (mostly for myself). Thank you!

    • Phoebe Moore (L&L Recipe Developer)

      Hi Jackie, so glad you love them!

  7. Susan Y

    I made them and YUM! I don’t consider myself a big onion person, but I saw them as part of a Swiss chard recipe you posted, so I decided to try them. They are tasty and perfect as an add-in for various recipes or meals. I’m glad you mentioned how you freeze portions that can be defrosted and used later. Thanks!

    • Jeanine Donofrio

      I’m glad you enjoyed the onions too!

  8. Jim

    5 stars
    Delisious. Mine took about 65 minutes. I removed from the pan tuned heat up to medium added butter and sliced mushrooms. Sautéed the mushrooms for 10 minutes then added the carmalized onions and topped our burgers with the mix. Awesome!

    • Jeanine Donofrio

      I’m so glad you loved them!

  9. MGM

    I hate onions (raw) but i love Vidalia onions cooked. and I love caramelized onions. I took a shot at this. and OMG. great! I didn’t have a cast iron pan. Used one of my big non-stick skillets. Perfect. Thanks.

  10. HRose

    Can you use a regular pan. I
    Do not own a cast iron pan.

    • Jeanine Donofrio

      yep, absolutely!

  11. Karen Who

    5 stars
    Thank you for sharing recipes. This is a perfect recipe. I used vidalias. Costco overabundance 😆. Patience is a virtue for good reason. I made extra in a 12 inch lodge cast iron pan. Started them while making breakfast it took all of 90 minutes but so well worth the wait. It really ups your game. I freeze them as described in silicone ice cube trays and once frozen drop them into a freezer container. Enhances store bought sauces for easier meals.

    • Jeanine Donofrio

      I’m glad you enjoyed the onions!

  12. Eric Harris

    5 stars
    I used 2 white and 2 yellow onions. Being July 4th I will use them as a side dish for our bbq steaks.

  13. HB

    5 stars
    These lovely caramelized onions also go extremely well with chicken liver paté and toasted bread!!! Just a suggestion!

  14. Sara F

    5 stars
    First time making these! Super simple! They are a commitment of time! Thanks for sharing!

  15. Arjun

    5 stars
    Thanks Jeanine for your detailed explanation of how to create caramelized onions. After reading this article, I must confess – I never knew how to make them. I thought I did, but honestly I didn’t know what I was doing. I had no idea that the size of the pan I used mattered, in fact come to think of it, I am not sure my friend mentioned that, a while back when she was explaining the process to me. And I didn’t know that while I varied the heat during the process, it was supposed to take as much as 45 minutes to make them. No wonder my caramelized onions never taste right. I thought by just keeping the heat high within 20 minutes tops I was done. Well, Jeanine you have been a life saver, thanks.

A food blog with fresh, zesty recipes.
Photograph of Jeanine Donofrio and Jack Mathews in their kitchen

Hello, we're Jeanine and Jack.

We love to eat, travel, cook, and eat some more! We create & photograph vegetarian recipes from our home in Chicago, while our shiba pups eat the kale stems that fall on the kitchen floor.