Caramelized onions are one of the most magical kitchen ingredients. Not only can they transform practically any dish with a sweet, oniony taste, but they are a dream come true for meal prep. They’ll last for a week, easily, making them a staple in our kitchen, no matter the menu
The simple combination of onions (we recommend Vidalia, or sweet onions!), butter, and Kosher salt, plus a lengthy low and slow cook time, results in a rich, deep, sweet flavor thanks to the natural sugars in the onions cooking down.
You’ll love these caramelized onions on everything savory from pizza and pasta to burgers and literally any breakfast (scrambled eggs, omelettes, benedicts!).
3 Simple Ingredients
When it comes to caramelizing onions, we’re purists. You’ll need onions, Kosher salt, and butter (or olive oil).
What type of onion is best for caramelizing? This is genuinely a trick question. You can use any type of onion you like! Vidalia onions, yellow onions, white onions, red onions, shallots — if it’s part of the allium family, you can caramelize it.
How Long Does It Take To Caramelize Onions?
This is definitely a low and slow process. You’ll need at least 45-60 minutes of cook time once the slices of onion hit the pan for them to cook down and release their natural sugars.
We recommend heating a cast iron skillet (though stainless steel is great too) over medium-low to medium heat, then melting the butter. Once melted add the onions (it looks like a lot, but trust us, it’ll cook down), then stir with a spatula or wooden spoon every few minutes, making sure to scrape the bottom of the pan to release any browned bits as they form.
Eventually, after 40 minutes or so, they onions will take on a deep, golden, caramel color. There’s no need to deglaze the pan (and you should shun any recipe that calls for balsamic vinegar — NO thank you!), the excess moisture released from the onions keeps them from drying out. Just make sure the heat isn’t too high!
Different Ways To Use Caramelized Onions
- On burgers or sliders!
- As a pizza topping!
- On sandwiches (these are mini grilled cheese sandwiches, and the onions add the perfect sweetness!)!
- As the base for French onion dip or French onion soup (yes, please!)
- Stir them into pasta sauces for a burst of sweet onion flavor!
Tips + Tricks
- Do not cook over medium-high or high heat!! The caramelization process and natural release of sugars happens when you cook the onion slices slowly, over medium-low heat. You just can’t rush this, or you’ll risk burning the sugars in the onions.
- Use a cast iron or stainless steel sauté pan! These retain heat better than nonstick.
- Season with Kosher salt once caramelized. Let all the sugars and moisture cook release from the onions, then season with Kosher salt.
How To Store Caramelized Onions
Place caramelized onions in an airtight container, then store in a fridge for up to 1 week, if not longer.
Caramelized onions are also freezer-friendly! You can place them in freezer safe containers or portion them in ice cube trays, then freeze for up to 3 months. When ready, simply defrost as needed or put the frozen cubes directly into hot soups or warm pastas, where they’ll thaw quickly and melt into the sauce. Yum!
Love the taste of sweet caramelized onions as much as we do? Then this recipe is an absolute must!!
If you’re ready to learn How To Caramelize Onions, this recipe is a must! If you try it at home, be sure to leave a review and rating below!
Try Adding Caramelized Onions To These Recipes Next!
- Cheeseburger Sliders
- Smashed Eggs On Toast
- Lemon Garlic Pasta with Shrimp and Scallops
- Green Goddess Sandwich
- Turkey Feta Burgers with Apple Cabbage Slaw
How To Caramelize Onions Recipe
- 6 Tbsp unsalted butter
- 5-6 medium Vidalia onions or any other kind of onion, peeled and thinly sliced into half moons, about 8-10 cups
- 2 tsp Kosher salt
- Heat the skillet. Place butter in a large cast iron or stainless steel skillet. Heat over medium heat until butter has melted.
- Sauté the onions. Add the sliced onions, then immediately turn the heat down to medium-low. Stir every few minutes, cooking the onions down until the natural sugar release and they take on a deep, golden brown color, about 45-50 minutes total.
- Season the onions. Season with 2 tsp Kosher salt, stir well, then taste and adjust seasoning as needed. Cook an additional 5-10 minutes, until the onions are nutty, caramelized on all sides, and almost breaking apart in the pan. Use warm or at room temperature.
- Caramelized onions will keep for at least 1 week in a fridge when stored in an airtight container.
- If frozen, caramelized onions will keep for up to 3 months.