Learn how to make caramelized onions in their most delectable form. Deeply golden and savory-sweet, they add rich depth and extraordinary flavor to everything from appetizers, pastas, hamburgers and much more.
The Secret to Great Caramelized Onions
Making caramelized onions is easy. Making amazing caramelized onions takes one more ingredient: time. Taking it slow. And the deep flavor you get from having the patience to do so is so worth it.
Enjoying a delicious plate of caramelized onion pasta is one of the great rewards. Check out more favorite ways to use caramelized onions further below.
Ingredients
Onions, olive oil, salt. That is all it takes to make great caramelized onions. No sugar needed!
Best Onions for Caramelizing
Yellow or Spanish onions are a great choice for their balance between sharp and sweet. “Sweet onions” will work too (they really just have less sulfur, like “sweet water” rivers just lack salt). Once cooked down with this stovetop method (not in a slow cooker/crock pot), they all resemble a beautiful deeply golden candied jam.
(Red onions, don’t come out as well because the beautiful purple color turns muddy, with no golden notes. As far as the taste goes, they turn out pleasantly sweet, but with less complexity than the other onions.)
Roughly chop the onions, nothing too exact.
How to Caramelize Onions
Caramelizing tempers the sharp pungency of onions into a graceful savory sweetness, almost like a candy, or as they say in Italy, caramello.
Taking your sweet time to caramelize the onions in two steps brings out sweeter, deeper flavors and beautiful golden copper colors. It takes about an hour. And it is worth it!
It is your choice, based on what you want the result to be. I have been making caramelized onions for about 20 years now, and have definitely tried shortcuts! What I found, though, was that it just was not worth my time — even though it took a quarter less time. While the shortcuts resulted in good-looking caramelization, the deep rich flavor was missing, resulting in a steep decline in satisfaction.
Both!
Step 1
First, slow-cook the onions covered on the lowest possible heat setting for 30 minutes, being careful not to let them color. (See photo with lid above.) This step is pretty hands-off, with occasional stirring.
Step 2
Then, uncover and sauté the onions on medium-high heat for around 30 more minutes.
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What do caramelized onions look like?
Caramelized onions should have caramel, copper and even bronze hues, and resemble a thick, deeply browned jam.
Can you caramelize onions in a slow cooker?
While you can caramelize the onions in a slow cooker, I do not recommend it, if you want them to turn out at their best. I highly recommend cooking them on the stovetop. Wondering if it might be okay just for the first step? Actually, even in the first step, the stovetop gives far superior results. Cooking the onions in a slow cooker yields onions with a mushy swollen texture and bland muddy color. First they become muddy beige, then in step two, become darker faster and browner—not in a pretty golden way, just in a brown way. The stovetop version makes much more attractive caramelized onions, with deeper flavors, beautiful colors and a pleasant jammy texture.
Tip: Don’t Halve the Recipe
I do not recommend halving the recipe. Caramelizing only one or two onions in a pan does not tend to work out well.
For one, it is easier to brown a large quantity than a small quantity of onions. Too few onions in the pan does not allow them to make enough of their own juices, making them easy to burn, even at low heat with the lid on. And once the lid is off, it tends to brown too fast, and not well, as it is again hard to keep from burning. This can be made easier by having more onions in the pan. Crowding the pan causes more steam to build up, providing the moisture needed during the slow cooking stage.
Secondly, to get at least twice the reward for the labor. It is a lot of time spent for just one dish. If you are going to look after these onions for an hour, make enough to enjoy multiple delicious dishes. I always thank myself later.
Make Ahead
I like to caramelize more onions than I need for one dish for a couple of great reasons, as discussed above. Double the recipe for several future portions and freeze them. This recipe caramelizes enough onions for four portions of caramelized onion pasta, for instance. Check out more favorite ways to use caramelized onions below.
Favorite Uses for Caramelized Onions
Caramelized onions, like a magic wand, add magic to whatever they are added to. I recommend making enough caramelized onions to have ready any time! Here are my favorite ways to use them:
- Pasta – Caramelized onion pasta with herbs – A wonderful pasta dish.
- French onion dip – Homemade is better!
- Soup – French onion soup, oh yes! Mushroom soup! Caramelized onions can add extra flavor and complexity to many soups.
- Green beans – Mix in right before serving, perhaps with a little fresh thyme. I always have seconds!
- Steak topping – Alone or blended with fresh herbs or sautéed mushrooms.
- Appetizer topping for toasts, crostini, bruschetta – Using toasted baguette slices. Mix in fresh herbs!
- Cheese – Enjoy as an appetizer, or for those who appreciate an excellent cheese to end their meal, as dessert. Savory-sweet caramelized onions are an excellent partner. Serve as an accompaniment in a small serving bowl with aged cheese or a cheese plate; or as a spread or stir-in with brie, goat cheese or other favorite cheese.
- Hamburger topping – If you have been wanting to up your hamburger game, let caramelized onions be the magic.
- Mashed potatoes – Just stir them in.
- Quiche or Tart – The secret to why yours is just so good!
- Grilled Cheese sandwich – Grill yourself a sandwich with caramelized onions, gruyere or compté cheese, a dijon/mayo blend, and sprinkling of thyme leaves.
- Focaccia Topping – Onion Focaccia is a classic. Caramelized onion focaccia? Well…
- Risotto with caramelized onions – One of the most subtly sublime meals you can think of.
Refreshing Your Kitchen & Home Afterwards
After making a batch of caramelized onions, I like to clear the sulfur compounds out of the air! My favorite way is by simmering a lemon on the stove. Before simmering, I cut the lemon in quarters and squeeze a little lemon juice into the water. (Caveat: the quality of the lemon counts — there are some less aromatic lemons in the market nowadays that are not as effective.) In nearby rooms, I like to light a candle with a natural pine scent.
Recommended Cooking Pan
I prefer to use a quality stainless steel saute pan or stainless steel pasta pan for caramelizing onions. Why? Because stainless steel allows the flavorful fond to be scraped up and sweated off the sides of the pan, meaning more flavor gets blended into the onions (yum), something a nonstick skillet is not so good at. And stainless steel does not muddy up the colors, like a cast iron skillet tends to do, when you need to add a bit of water here and there for deglazing (or to prevent scorching).
For this recipe, I like to use a pan no bigger than 9 inches (24cm) in diameter, so that the onions take up enough space to keep the sides of the pan from scorching.
Recipe
Tools
- Quality heavy-bottomed stainless steel saute pan or pasta pan
Ingredients
- 3 large onions, chopped
- 3 Tbsp olive oil
- 1 pinch of sea salt
Instructions
- Slow-cook – Stir together chopped onions, olive oil and salt in a heavy stainless steel pan. Cover, and cook over the lowest possible heat setting for 30 minutes, stirring occasionally. Be careful not to let the onions color. (If needed at any point, stir in just enough water to moisten the onions.)
- Caramelize – Uncover, and sauté onions on medium-high heat until deeply caramelized to golden brown, about 30 minutes.Frequently scrape the brown glaze from the bottom of the pan with a wooden spoon or metal spatula, being careful not to let the onions, nor the glaze on the bottom of the pan, burn.(Lower the heat if necessary. If just a small area of the glaze on the bottom of the pan starts to char, pour a spoonful of water directly over it and, using the wooden spoon, quickly rub it with the onions to dissolve it.)
- Cover and let the onions sit undisturbed off the heat for 5 minutes. Then uncover and stir the deeply flavorful glaze detached from the pan into the onions.
Nutrition Info: Click to Expand
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