Have you always wanted to learn how to caramelize onions? We’ve got you covered. The key to making caramelized onions is to cook them low and slow over low heat.
You only need onions, olive oil, and salt to make a big batch of these easy and delicious caramelized onions.
Stove Top Caramelized Onions
Raise your hand if you love caramelized onions on everything? We are big fans of making a big batch of caramelized onions in the refrigerator so we can use them on burgers, omelettes, salads, and more.
Follow this caramelize onion recipe and feel free to double or triple the recipe and store them in the refrigerator for a week.
Why you’ll love it!
Reasons why you’ll love it.
Caramelized onions make everything better. They had a savory and sweet flavor that few condiments add to recipes. They truly are one of a kind.
Once you master caramelized onions, you will make them all the time.
- Yellow onions: we generally use yellow onions when we make caramelized onions because they offer a simple sweetness to the caramelized onions.
- Olive oil: use quality olive oil to use for this recipe. It will make the onions all the better.
- Salt: salt is a very important ingredient in this recipe. You add salt to draw out the moisture of the onions and to bring out the delicious flavor of the onions.
Can I use any type of onion for caramelized onions?
Yes, you can use any type of onions to make caramelized onions. Every type of onion has a slightly different flavor or specialty.
- White onions have a strong onion taste and tend to break down a bit easier. Be sure to watch these onions, they may take less time to cook.
- Yellow onions have a more mild onion flavor that tend to have a mild sweetness to them.
- Purple onions tend to loose their color when cooked and have a delightful and sweet flavor.
How to Slice Onions for Caramelized Onions
When preparing onions for caramelized onions, you want to make sure the onions are about 1/4-1/2-inch thick. Any thinner and the onions will disintegrate while being cooked.
We also recommend that you slice all of the onions relatively the same size. You can use a sharp knife to slice them into thin strips or you can use a mandolin to ensure they are all the same exact size.
How to Caramelize Onions on the Stovetop
- Peel the onions and then slice the onions to about the same thickness.
- Heat a large skillet or cast iron skillet over low heat and add the olive oil. Add the onions to the pan and toss with the oil. DO NOT add the salt to the pan yet. Cook the onions in the oil for 30 minutes.
- After 30 minutes, add the salt to the onions, toss, and cook for an additional 30 minutes.
- When the onions begin to brown and taste deliciously sweet, remove them from the heat and serve immediately or let them cool and store them for later in the refrigerator.
Caramelized Onions in the Oven
Want to try making caramelized onions in the oven? We’ve got you covered. Check out how to caramelize onions in the oven here.
Be sure you don’t slice the onions too thin or they will disintigrate.
Do not add the salt to the onions right away. You add the onions half way through the cook time so the onions don’t cook in their own liquid too early.
Caramelized onions are meant to be cooked very low and slow. This should take 50-60 minutes!
What type of pan you use matters. Cast iron pans and nonstick pans cook differently. Both pans work, but be sure you keep an eye on your onions not matter what type of pan you use.
How long does it take to caramelize onions on the stove?
It takes about 1 hour to make properly caramelized onions on the stovetop.
Is it better to caramelize onions in butter or oil?
You can use butter or oil when you caramelize onions. It’s a personal preference. We prefer olive oil.
Why do I add salt halfway through the cook time for caramelized onions?
If you add salt too soon in the cooking process, it will release the moisture from the onions too soon and then the onions will “boil” in the onion liquid and begin to disintegrate.
Do I need to add baking soda to the onions when I make caramelized onions?
Some people like to add baking soda to onions to encourage them to brown quickly. We try to avoid adding baking soda and do it the good ole fashion way. Baking soda also tends to alter the taste of the caramelized onions.
Let the caramelized onions cool completely and then store them in an airtight container. Store them in the refrigerator for up to 7 days.
How to Caramelize Onions
- Use a mandolin or a very sharp knife to slice all 4 onions into even slices to about ¼” to ½-inch thick.
- Heat a large, cast iron skillet over low heat and add the olive oil. When the olive oil is fragrant, add the onions.
- Toss the onions with the olive oil and let the onions cook on low for 30 minutes, stirring periodically.
- After 30 minutes, season the onions with salt, stir, and let the onions cook for another 20-30 minutes over low heat, stirring periodically.
- When the onions turn a golden brown color and are caramelized, remove them from the pan.
- Use the caramelized onions on burgers, on salads, wraps, sandwiches or however you would like.
Tips & Notes
- Do not add the salt to the onions right away. You add the onions half way through the cook time so the onions don’t cook in their own liquid too early.
- Caramelized onions are meant to be cooked very low and slow. This should take 50-60 minutes!
Photography: photos taken in this post are by Ashley McGlaughlin from The Edible Perspective.