Make Caramelized Onions in 7 Easy Steps

Caramelized onions bring irresistible flavor to burgers, soups, pizza, sandwiches and so much more. Mastering how to make caramelized onions is as simple as one key ingredient: time.

Try this caramelized onion and balsamic vinegar jam while you have onions on your mind!

What Kind of Onions are Best for Caramelizing?

Any type of onion will work for caramelizing. Compared to red and white onions, yellow onions and other sweet varieties have naturally higher sugar content and will therefore caramelize even more easily.

The Vidalia onion is a type of bulbing onion, produced in Georgia. The low sulfur content of the soil results in a sweet flavor.

Tips and Tricks for Making Caramelized Onions

Caramelizing onions is a relatively straightforward process, but here are the best keys to get amazingly delicious results every time:

Low and slow is the key. To achieve perfect caramelization, you need to slowly release the natural sugars in the onions so they caramelize steadily without burning. 

Cook over medium heat for up to one hour. You want enough heat to let time work its magic on those sugars without burning them. Don’t worry: you don’t have to stir constantly. Every few minutes will do the trick! As the onions cook, you may reduce the heat further, to medium low.

Cast iron or stainless steel pans give the best results. These pans allow the sugars to naturally build up and stick to the pan a little, which results in that delicious caramelized flavor. Scraping every few minutes prevents the sugars from building up and burning.

Deglaze for added flavor. If you notice your onions getting a bit dry toward the end, add a touch of port wine, broth, light beer, or balsamic vinegar and stir to deglaze the pan. This dissolves the sugar buildup and adds an extra depth of flavor.

Batch cook and freeze. Since caramelizing onions takes about an hour no matter how many onions you cook, you might as well cook a big batch and freeze the extras! (See more on freezing later.)

How to Caramelize Onions in 7 Easy Steps

1. Peel, halve, and slice 3-4 large onions.
2. In a large sauté pan, heat olive oil (about one teaspoon per onion) over high heat.
3. Add onion slices, stir to coat with oil, and then reduce heat to medium.
4. Cover onions for 10 minutes to speed softening (this will save you a few minutes of cooking time). Then, uncover and sprinkle the onions with salt.
5. Stir every 5-10 minutes, allowing sugar to brown on the bottom of the pan and then scraping thoroughly every time you stir. As cooking progresses, stir every 1-2 minutes.
6. As onions brown, if they become dry, add a splash of wine or vinegar to deglaze the pan and enhance flavor.
7. Remove from heat and cool before storing.

Do you need added sugar for caramelizing onions?

Adding a touch of white or brown sugar is an old trick to try and make onions caramelize faster. It works to some extent, but it can easily overwhelm the flavor of your onions with too much sweetness. Onions have plenty of natural sugars for the caramelizing process – they just need the right time and temperature to release them.

Which is better for making this caramelized onion recipe: butter or olive oil?

Butter adds another dimension of flavor to your onions, but it does tend to burn easily. Because of this drawback, olive oil is a safer bet for caramelizing onions. Some cooks recommend using a 50/50 mixture of olive oil and butter so you can have the best of both worlds.

Can you refrigerate or freeze caramelized onions?

Yes! You can store them in the fridge for up to one week in an airtight container. Freeze your caramelized onions in ice cube trays and then transfer to a freezer safe bag or container. Store in the freezer for up to 3 months.

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