Caramelized onions are made by cooking onions low and slow until golden, delicious, and intensely flavorful and learning how to properly caramelize onions is key. Learn how with this easy step-by-step tutorial.
You’ll use them to make French onion soup and onion dip, to top your favorite burgers or add flavor to rice and grains, but how, exactly, does one make caramelized onions?
This is an excellent question and one I will answer throughout this post.
Before diving headfirst into the process of cooking caramelized onions, however, let’s start with some basics.
How Long Does it Take to Cook Caramelized Onions?
It takes approximately 45-60 minutes to cook caramelized onions. It’s a long process, but well worth the wait.
Why does it take so long to caramelize onions?
To draw out the natural sugars found in onions (those which are responsible for caramelization), the onions must be cooked at a low temperature for a long period of time. Cooking at a higher heat or attempting to “rush” the process, will cook off the moisture too quickly, preventing the sugars from being drawn out properly. and ultimately results in burnt, flavorless onions.
What is the Difference Between Caramelized Onions and Sauteed Onions?
The difference between caramelized and sauteed onions is determined by cooking temperature and cooking time.
When sauteing onions, it’s a relatively fast process. Cooked using a higher temperature (between medium-high to high heat), the onions are browned on just the outside, taking about 10 minutes rather than a full hour or so.
How to Caramelize Onions
To make these delicious jammy caramelized onions, you’ll need the following tools and equipment:
- Chef’s knife
- Heavy-bottom pan or large skillet – a large Dutch oven will also work
- Metal spatula
- Cutting board
For the full list and amounts of ingredients, scroll down to the recipe card at the bottom of the page.
1. Prepare the onions
Use a sturdy knife to slice approximately 1/2-inch off from each stem-end and approximately 1/2-inch off from each root-end of the onions. Cut each onion in half, stem to root, and peel. Lay the onions cut-side-down and cut, again from stem to root, into slices approximately 1/4 to 1/2-inch thick. Repeat with all onions.
- How thick should you cut your onions? This is largely based on personal preference. Ideally, you want onions that are not too thick and not too thin. A safe bet is anything between 1/4-1/2-inch.
2. Start cooking the onions
Set a large, heavy-bottomed sauté pan or cast-iron skillet over medium-high heat to medium heat. Add the olive oil and butter (if using) and swirl to coat the bottom of your pan. Heat the oil until shimmering and hot, then add the sliced onions. Mix well to coat the raw onions in oil.
- TIP: Keep this recipe vegan by skipping the butter.
3. Continue cooking the onions
Allow your onions to cook, stirring occasionally. If you start to see your onions browning, immediately reduce heat to medium-low heat or low heat.
Remember, the caramelization process is low and slow.
After approximately 10 minutes, sprinkle with salt (approximately 1/2 teaspoon) and stir to combine. By this point, your onions should be softening and lightly golden.
- TIP: If your onions start to dry out and brown/burn prematurely (assuming your heat is already set to medium-low), add a few teaspoons of water to the pan.
4. Continue to cook, stirring often
Continue to cook your onions for an additional 30-45 minutes, stirring every 2-3 minutes to prevent burning.
You don’t want to stir continuously, but just often enough that the onions have enough time to cook and stick to the bottom of your skillet, browning just slightly – but not burning. If you stir too often, they won’t brown. If you don’t stir often enough, they will burn.
I like to keep my stovetop set to medium-low and cook my onions for at least 50-60 minutes.
5. Use a metal spatula to scrape the pan often:
After about 30 minutes, your onions should be a rich golden color.
Every minute or so, use a metal spatula to scrape up the brown bits from the bottom of your skillet.
Continue to cook, stir, and scrape the brown bits (fond) from the bottom of the pan until your onions are a dark rich golden brown color.
Remove from heat and serve with all your favorite recipes including mac and cheese, quiche, grilled cheese sandwiches, and salads.
Tips & Tricks
- Turning up the heat won’t caramelize your onions faster. Don’t rush it, caramelizing onions is a science.
- Do not walk away from your onions. Unlike the slow cooker or Instant Pot, you need to remain proactive when caramelizing onions. This is especially important in the second half of cooking when the fond really starts to build up.
- What is fond? The sticky brown bits stuck to the bottom of your skillet.
- How to prevent fond from burning? First, make sure your stove is set to medium-low or low and use a metal spatula to scrape the bottom of your pan every 1-2 minutes. You can also deglaze your pan with a bit of water.
- What onions are best for caramelized onions? Vidalia or white onions.
- Storage: Keep leftovers stored in an airtight container and in the refrigerator for up to one week or freeze in sealed ziplock bags for up to 3 months.
Recipes with Caramelized Onions,
Cheesy Mashed Potato and Herb Stuffed Mushrooms
Quinoa Salad with Garlic Roasted Butternut Squash
Blueberry and Honey Caramelized Onion Naan Pizza
Cranberry Wild Rice Pilaf with Sweet Potatoes
Roasted Eggplant and Caramelized Onion Farro Salad with Walnut Mustard Dressing
Learn how to make caramelized onions and let me know how they turn out! I always love to read your thoughts and feedback!
REMEMBER TO SUBSCRIBE TO THE FORKED SPOON NEWSLETTER FOR FREE AND RECEIVE WEEKLY RECIPE NOTIFICATIONS DELIVERED STRAIGHT TO YOUR INBOX!
How to Caramelize Onions
Ingredients
- 5 large onions (yellow, white, or red)
- 2 tablespoon olive oil
- 1 tablespoon butter ((optional))
- salt
- balsamic vinegar ((optional))
Instructions
- Prepare the onions: Use a sturdy knife to slice approximately 1/2-inch off each stem end and roots off the root end. Cut each onion in half, stem to root, and peel. Lay the onions cut-side-down and cut, again from stem to root, into slices approximately 1/4 to 1/2-inch thick. Repeat with all onions.
- Start cooking the onions: Set a large, heavy-bottomed sauté pan or skillet over medium heat. Add the olive oil and butter (if using) and swirl to coat the bottom of your pan. Heat the oil until shimmering and hot, then add the onions. Mix well to coat the onions in oil.
- Continue to cook your onions: Allow your onions to cook, stirring occasionally. If you start to see your onions browning, reduce heat to medium-low (remember: we're cooking these onions low and slow). After approximately 10 minutes, sprinkle with salt (approximately 1/2 teaspoon) and stir to combine. By this point, your onions should be softening and lightly golden. If your onions start to dry out and brown/burn prematurely, as a result, (assuming your heat is set to medium-low), add a few teaspoons of water to the pan.
- Continue to cook, stirring often: Continue to cook your onions for an additional 30-45 minutes, stirring every 2-3 minutes to prevent burning. You don't want to stir continuously, but just often enough that the onions have enough time to cook and stick to the bottom of your skillet, browning just slightly - but not burning. If you stir too often, they won't brown. If you don't stir often enough, they will burn. I like to keep my stove set to medium-low and cook my onions for at least 50-60 minutes.
- Use a metal spatula to scrape your pan often: After the first 30 minutes, you'll find that your onions are nice a deeply rich golden color. Every minute or so, use a metal spatula to scrape up the brown bits from the bottom of your skillet. Continue to cook, stir, and scrape the brown bits from the bottom of the pan until your onions are a rich golden brown color.
- Serve or store: Remove from heat and serve with all your favorite recipes or transfer to a sealed container and keep stored in the refrigerator for up to 4 days.
Jessica's Notes
- Variations: At the end of cooking deglaze your pan with a splash of balsamic vinegar or red wine. This is completely optional, but it adds a delicious, complex flavor to your onions (highly recommended when adding your onions to pizza or pasta).
- Turning up the heat won't caramelize your onions faster. Don't rush it.
- You may use any type of onion, but yellow onions, sweet onions, red onions, or white onions are best.
- How to prevent fond (sticky brown bits) from burning? Make sure the heat is set to medium-low or low and use a metal spatula to scrape the bottom of your pan every 1-2 minutes. You can also deglaze your pan with a bit of water.
- Some people add a teaspoon of regular or brown sugar at the same time that the salt is added (approx 10 minutes into cooking). I find this unnecessary.
- Storage: Keep stored in the refrigerator for up to one week or freeze in sealed ziplock bags for up to 3 months.
- Caramelized onions are naturally gluten-free and vegetarian.
Nutritional Information
(Nutrition information provided is an estimate and will vary based on cooking methods and specific brands of ingredients used.)
Last Updated | 1 Comment