How to Make Caramelized Onions
Caramelized Onions are one of the most delicious toppings for sandwiches, burgers, and so many various appetizers. Make sure to cook them slowly and carefully, that way, the natural sweetness of the onions and that signature caramel color develop the best flavor possible.
To add more flavor to your favorite sandwiches, try my other toppings like Sun-Dried Tomato Pesto and Garlic Aioli.
Table of Contents
Let’s start right at the top with the most important piece of information you can know about making caramelized onions – it will take time! The key to making the best, sweet and slightly nutty caramelized onions is cooking them SLOWLY! While I typically like a good shortcut, there’s no way to cut down on time here.
If you try to raise the heat while cooking your onions, you’ll just end up searing them instead of caramelizing them!
With all of that being said, taking your time to make real caramelized onions is so worth your patience. There is an endless list of appetizers, sides, sandwiches, burgers, and more that all benefit from the addition of these onions!
Similarly to roasted garlic, caramelized onions add something special to everything they’re served with! They add a rich flavor that’s both savory and sweet, as well as soft and smooth consistency, which is usually a nice contrast to whatever they’re paired with.
Ingredient Notes
Yellow Onion – for best results, use yellow onion or Vidalia onion. Remember that Vidalia onion has more natural sweetness.
Olive Oil – use a neutral oil like avocado, vegetable, or canola oils.
Sugar – A light sprinkle of white granulated sugar helps the process of caramelization by bringing out more natural juices and sweetness of the onions.
Butter – use unsalted butter to help keep the onions from drying out.
Deglazing Liquid – You can use water, broth, or white wine to deglaze your pan. It all depends on what flavor you’d like to be lent to your onions. Broth is the best option to enhance the flavor, and remember that wine will add a different flavor.
See recipe card for complete information on ingredients and quantities.
How To Make Caramelized Onions
Prepare the onions.
Cut the onions in half first, then cut off the tip, peel the outer skin off, and slice the onion in thin strips to the root.
Cook the onions.
Add oil to a pan preheated at medium heat. To the pan, add your onions, salt, and sugar (1). Mix everything together so that the onions are coated with both the salt and sugar as well as the oil.
Lower the heat to medium – low. Stir the onions every 5-10 minutes as they cook (3). They’re going to look white for a while – this is to be expected, so don’t worry! As they cook slowly, they’ll release liquids and then start to turn golden brown after that (4).
When all the onions turned golden but not quite caramelized yet, add butter and let it melt (5). Mix it in and continue to cook the onions slowly unto completely deep golden (6).
Deglaze the pan if needed: The sugary liquids from the onions will likely settle on the pan, but this also depends on what kind of pan you’re using. To deglaze, simply scrape the pan as you deglaze it with a splash of liquid of your choice. (Water, broth, and white wine all work well.)
Remember to be patient!
The total cook time for your caramelized onions will be around 45 minutes to an hour. Stir the onions from time to time, deglaze and add butter as needed, and don’t increase the temperature. Then, once they’re soft, golden brown, and fully caramelized… Enjoy!
Frequently Asked Questions
Onions, much like many other vegetables that are mostly composed of liquid, shrink down significantly after cooking. So the 1 pound (or 2 large onions) you cook will only give you approximately 1/2 cup of caramelized onions.
Cooking the slow! The total cook time for your caramelized onions will be around 45 minutes to an hour. As they cook slowly, they’ll release liquids and then start to turn golden brown after that. Stir the onions from time to time, deglaze and add butter as needed, and don’t increase the temperature. If you increase the temperature, you will sear the onions instead.
Absolutely! This is a great make-ahead recipe. Simply make a batch, cool it, and store in the refrigerator, in an air-tight food storage container. When you need some, get some up and reheat it for a few seconds in the pan or microwave. Caramelized onion should be good in the fridge for up to a week when properly stored.
How to Serve Caramelized Onions
The possibilities here are truly limitless. Just to name a few serving suggestions:
Sandwiches, hot dogs, sliders, and grilled cheese.
Burgers and chicken burgers,
Pizza and flatbread toppings,
Cheese board,
In dips (think French Onion Dip and more)
Mixed with pasta and casseroles,
On top of nachos, tacos, and crostini
Tips for the Best Caramelized Onions
- Use a large pan because you will need a good amount of space until the onions shrink down.
- Do not raise the heat! Cook the onions over medium low heat for the duration of the cook time.
- Stir often, every 5-10 minutes, to make sure all of the onions cook evenly.
- Keep cooking until the onions turn a deep caramel color. Don’t quit until you’re all the way done!
- If the onions and the pan look a little dry while cooking, add some butter.
- Depending on the pan you’re using, the sugary liquids that cook out of the onions can settle on the pan. Simply scrape the pan as you deglaze it with a little liquid.
Storing and Freezing Instructions
Store caramelized onions in the refrigerator, in an airtight food storage container. Properly stored, they should stay good for up to a week.
You can always make a bigger batch and freeze them! Make sure to cool the onions completely before freezing them, then portion them into ice cube trays or a muffin pan (try using silicone muffin pan or line it with parchment paper). Set a timer and freeze them for 2-3 hours, then pop the frozen onion “cubes” into a freezer zip-top bag. Freeze it for up to 3 months.
More Recipes To Try
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Caramelized Onions Recipe
Ingredients
- 1 lb yellow onion
- 1-2 tbsp olive oil
- 1 tsp coarse salt
- 1/2 tsp white granulated sugar
- 1 tbsp butter optional
- 2-4 tbsp deglazing liquid such as water, broth, or white wine if needed
Instructions
- Cut the onions in half, through the root end to the top. Cut off the tip, peel the outer skin, and slice onion thinly to the root. Discard the tip and the root.
- Heat up a cooking pan over medium heat and add oil. Add sliced onions and season with salt and a little sugar. Mix onions to evenly coat them with oil and seasoning. Lower the heat a little and cook onions over medium-low heat.
- Stir onions every 5-10 minutes as they cook. The onions will look white for a while, they will release liquid and cook down slowly and will start to get golden and brown after that.
- Depending on the pan you're using, the sugary liquids that cook out of the onions can settle on the pan. Simply scrape the pan as you deglaze it with a little liquid. (Choice for liquid can be water, broth, or wine.)
- The total time will take 45-60 minutes. Make sure to stir from time to time as onions are cooking and caramelizing. Don't try to rush it or raise the heat because the onions will sear instead of caramelizing. Wait for them to naturally caramelize and brown.When onions are almost done, add a little butter and stir it in.
Notes
- Use a large pan because you will need a good amount of space until the onions shrink down.
- Do not raise the heat! Cook the onions over medium low heat for the duration of the cook time.
- Stir often, every 5-10 minutes, to make sure all of the onions cook evenly.
- Keep cooking until the onions turn a deep caramel color. Don’t quit until you’re all the way done!
- If the onions and the pan look a little dry while cooking, add some butter.
- Depending on the pan you’re using, the sugary liquids that cook out of the onions can settle on the pan. Simply scrape the pan as you deglaze it with a little liquid.
Nutrition
All images and text ©Lyubov Brooke for ©Will Cook For Smiles. Please do not use my images without prior permission. If using my posts in collections and features, please link back to this post for the recipe.
Disclaimer: Nutrition information shown is not guaranteed to be 100% accurate as most ingredients and brands have variations.
I made these to put on top of our hamburgers tonight and they were so good!
Have you tried them in bagels? I recently attended a class that showed how to make bagels and they added caramelized onions into bagels. Everyone loved them.
No, I haven’t but that is a great idea! I will be giving that a try! 🙂