Learning how to caramelize onions has changed the cooking game for me! They’re so perfectly sweet and savory, and they improve every dish I add them to. Plus, they’re surprisingly easy to make. All you need is a little patience. Caramelized onions are my secret ingredient for insanely flavorful dips, dinners, and more!
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Before I show you how to caramelize onions, let’s talk about what it means to caramelize something. It’s the same process that’s used to make caramel, but you can “caramelize” lots of things that contain natural sugars, including onions! What you’re doing is bringing out the natural sugars within the onion while cooking so that you can really taste the sweetness. These caramelized onions are a total flavor game-changer!
What’s in This Caramelized Onions Recipe?
- Onions: You can use any kind of onion, but I prefer yellow onions because they have the best flavor balance. Sweeter onion varieties generally caramelize best because they have a higher sugar content, but again, any onion will work (including red onions).
- Butter + Olive Oil: Using butter (in addition to oil) adds a beautiful richness to the flavor.
- Spices: You don’t necessarily need seasoning but I like to add salt and pepper plus fresh thyme leaves to enhance the savoriness.
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Tips for Success
- Onions will cook down significantly, so what looks like a lot in the beginning will yield much less in the end.
- Make sure you’re using a large pan/skillet to avoid overcrowding the onions.
- Keep the temperature low to avoid burning.
- Let the butter melt fully, coating the pan as it melts, before you add in the onions.
- Stir the onions regularly to make sure they cook evenly, and to prevent sticking.
- Add a splash of water to the pan as needed if the onions start to stick or burn.
- Adding sugar to the pan will speed up the process, but I have found that it makes the onions too sweet, so I don’t recommend it.
- Be patient! You can get great results in about 20-25 minutes of cooking, but you can also continue on longer for even sweeter, softer, darker onions.
- I highly recommend making caramelized onions in big batches ahead of time and storing them in the refrigerator. This process can take some time, so having them ready in the fridge will speed up all your weeknight recipes. This is something you could do during your weekly meal prep!
How to Store and Reheat
Store leftover caramelized onions in an airtight container in the refrigerator for up to 1 week or freeze them flat in resealable bags or in small portions in ice trays for up to 3 months. Simply add the onions to a dish and allow them to reheat as the dish cooks, or reheat them in the microwave in 30-second bursts until warmed through.
Serving Suggestions
Caramelized onions are my secret weapon! They add a complex, sweet yet savory flavor to any dish. They’re a staple for French onion soup, patty melts, and all kinds of recipes. Add them to burgers, pastas, soups, pizza, and more. Or serve them on the side alongside a juicy steak.
Some of my favorite recipes to add them to are caramelized onion Swiss burgers, caramelized onion bacon dip, hot onion souffle dip, French onion chicken skillet, and butter burgers.
5-Star Review
“I have tried making caramelized onions before and they were meh. Your emphasis on “patience” really resonated with me. The water tip is invaluable. The video was another plus. THANK YOU!” -Margaret
How to Caramelize Onions
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Ingredients
- 1½ tablespoons extra-virgin olive oil
- 2 tablespoons unsalted butter (¼ stick)
- 1 pound yellow onions peeled and thinly sliced
- 1 teaspoon fresh thyme leaves
- ¼ teaspoon kosher salt
- ⅛ teaspoon freshly ground black pepper
Instructions
- Add the oil and butter to a medium-large skillet set over medium-high heat.1½ tablespoons extra-virgin olive oil, 2 tablespoons unsalted butter
- Once the butter is melted, add the onion, thyme, salt, and black pepper.1 pound yellow onions, 1 teaspoon fresh thyme leaves, ¼ teaspoon kosher salt, ⅛ teaspoon freshly ground black pepper
- Cook until the onions start to turn brown in spots, about 5 minutes, stirring frequently.
- Turn the heat down to low, cover the skillet, and cook 15 minutes more, stirring occasionally. Add a splash of water as necessary if the onions start to stick to the pan or if the pan starts to get too dark.
Last step! Don’t forget to show me a pic of what you made! Upload an image or tag me @thecookierookie on Instagram!
Becky’s tips
Nutrition Information
How to Caramelize Onions Step by Step
Melt the Butter: Add 1½ tablespoons of extra-virgin oil and 2 tablespoons of unsalted butter to a medium-large skillet set over medium-high heat.
Add the Onions: Once the butter is melted, add 1 pound of peeled and thinly sliced yellow onion, 1 teaspoon of fresh thyme leaves, ¼ teaspoon of kosher salt, and ⅛ teaspoon of ground black pepper.
Cook the Onions: Cook until the onions start to turn brown in spots, about 5 minutes, stirring frequently.
Continue to Cook and Stir: Turn the heat down to low, cover the skillet, and cook 15 minutes more, stirring occasionally. Add a splash of water as necessary if the onions start to stick to the pan or if the pan starts to get too dark.
Great recipe! I use a cast iron Dutch oven to make a big batch, and use a bit more oil & butter, but FITST, I put the onions in the Dutch oven on the stove with a couple bottles of good beer and steam the onions for a few minutes. Give an extra depth of flavor! And if I’m making brats or other sausage, I put those on top of the onions until they “puff up” a bit before I put them on the grill. Drain any excess beer from the onions, and then proceed as you’ve stated!
You know they are done when you can’t stop eating them straight from the skillet!
Can the recipe be doubled?
Absolutely!
Fantastic! Took a while I prob had two pounds of onions. But so good.
I have tried making caramelized onions before and they were meh. Your emphasis on “patience” really resonated with me. The water tip is invaluable. The video was another plus. THANK YOU!
Thank me now or later but you don’t have to stand by the stove for an hour. Cut a ton and do them overnight in the slow cooker with no fuss! I added a tiny bit of oil to the bottom first. Portion those babies out and freeze or can them for an instant treat!
Thanks for stopping by!
I used the recipe and added banana peppers. Instead of adding water, I added beef stock and Philly sub oil. It was perfect for my slow Roasted London Broil French dip sub.
It says 20 minutes…it’s not that long. Not everyone has a slow cooker 🤷🏽♀️ thank you for this recipe! Used it to make a small batch to go with my one burger for myself for lunch 🥰