Learn how to caramelize onions perfectly every time. This basic cooking skill is easy, and caramelized onions add so much flavor to so many recipes.
What’s in this Caramelized Onions Recipe?
Caramelized onions are the secret ingredient you’re probably not using enough. You won’t need much to make caramelized onions, just a few kitchen tools you probably already have, as well as a few simple ingredients.
- Onions: Use yellow onions or sweeter varieties when caramelizing.
- Butter + Olive Oil: Using butter (in addition to oil) adds a beautiful richness to the flavor.
- Seasoning: You don’t necessarily need seasoning but I like to add salt and pepper plus fresh thyme leaves to enhance the savoriness.
Pro Tip: While I love to caramelize sweet onions, you can caramelize any type of onion.
What’s the Difference Between Caramelizing and Sautéeing?
While the general process at first seems to be the same, caramelizing and sauteing are two different cooking methods.
Sautéeing uses high heat, encourages quick browning, and overall takes a shorter amount of cooking time. It’s also going to create a crispier texture and a different kind of flavor.
Caramelizing, on the other hand, does start off by essentially sauteing the onions, but then it goes far beyond that. Most of the cooking time will be done on low heat, and will cook much longer. With this method, you’ll get a soft texture and sweet flavor.
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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.
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).
You don’t need to cut them in a certain way for this cooking method. You can cut them different ways depending on how you want to serve them. However, typically they’re cut into thin slices or diced.
No! Onions already contain natural sugars, which is why they’re so perfect for caramelizing. This process brings out those sugars to make them more prominent. Adding more sugar would make them too sweet and mess with the flavor.
Here’s the most important thing to remember for this recipe: making caramelized onions takes time! You’re cooking on low heat, and the caramelization process is generally slow. Don’t rush it. 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. Some people will cook them for up to an hour, but you don’t have to go that long if you don’t want to.
First of all, remember that this takes time. So 10-15 minutes in, you might just need to wait and let them keep cooking. It’s also possible that your pan is too crowded; with all the water being released from the onions, it could be slowing down the process. This is why you need a large pan or skillet.
You should be cooking them on low heat, so that’s the best way to prevent them from burning. Keep an eye on them and adjust the heat if necessary. Also, stirring regularly will keep them from sticking to the pan (which will cause them to burn). Lastly, add a splash of water as needed to prevent sticking and burning.
The onions will brown as they caramelize, but how dark depends on your preference. After just 20 minutes, they should be in the dark yellow to light brown range. Within 40 minutes, you’ll have a much deeper, caramelized brown color.
How to Make Ahead and Store the Best Caramelized Onions
I highly recommend making caramelized onions in big batches ahead of time and storing them in the refrigerator for up to 1 week. 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 Freeze and Reheat Quick Caramelized Onions
Freezing caramelized onions is a great idea since they take so long to make. You can make up a large batch of onions and freeze them flat in resealable bags, or use ice trays to freeze them in smaller portions. They will keep 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.
What to Serve with Easy Caramelized Onions
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, French Onion Soup Casserole, Caramelized Onion Bacon Dip, Hot Onion Souffle Dip, French Onion Chicken Skillet, and Butter Burgers.
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
- 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.
- Add a splash of water to the pan as needed if the onions start to stick or burn.
- Let the butter melt fully, coating the pan as it melts, before you add in the onions.
- Be sure to use unsalted butter for this recipe.
- Stir the onions regularly to make sure they cook evenly, and to prevent sticking.
- If you want to change up the flavor, you can add various spices and herbs while cooking. You can also cook along with garlic, or add a little bit of broth while they caramelize.
- Perfect caramelized onions take some time and attention, so have patience. The flavor will be worth it!
Nutrition Information
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 🥰