How to Caramelize Onions- Sauteed Onions Recipe
If you’ve ever wondered how to caramelize onions versus just saute them, read on!
Sweet, sticky and ambre hued caramelized onions are perfect on sandwiches side and more. Learn how to caramelize onions here!
Caramelized onions are not simply sauteed onions. Let’s get technical: it is a product of the Maillard reaction, which is a chemical reaction between amino acids and reducing sugar and requires heat.
Make sure to PIN How to Caramelize Onions!
For caramelized onions, a small amount of sugar is added in addition to the sugars released from the onion itself. A small amount of butter is also used to provide lubrication.
Any type of bulb onion can be used, as they all have sugar, but white or yellow onions look prettier. Red onions will have the flavor, but not be as visually appealing with a funky color.
Caramelized onions are not simply sauteed onions.
I tend to use a sweet onion, purely because that is what I have always used, but it is not necessary.
Put simply, here is how to caramelize onions….
A Couple of things to keep in mind for caramelizing onions:
ONE. Cut onions into as uniform of slices as you can. Thicker onions take longer to cook, thinner less time to cook. Ideally you would like your onions to all caramelize at the same pace.
TWO. This is a slow process. Trying to speed it up with produce sauteed onions, but they will lack the sweet taste you are trying to achieve. Be patient.
THREE. Use a large frying pan, preferably with a heavy bottom. This provides the largest amount of cooking surface and allows you to better control the temperature.
FOUR. Don’t over stir. Stirring too much will result in mushy onions. Use more of a tossing maneuver to rotate onions. You will need to toss more towards the end of cooking.
FIVE. I add a teaspoon of sugar to my onions, but many do not. Your choice, you can leave it out using only the sugar naturally produced by your onions.
SIX. Depending on your pan, you may have some sticky, brownish bits stuck to the bottom of your pan. No worries, you didn’t burn your onions. Just de-glaze with a splash of white wine and scrape them up.
SEVEN. Caramelized onions freeze well and can be kept in the refrigerator for up to 4 days.
EIGHT. Caramelized onions also freeze well in airtight plastic bags.
Tools for making caramelized onions:
Heavy Bottom Frying Pan– this will be one of your most used kitchen tools. Having something that is heavy bottom will distribute heat better and prevent burning whether you are using an electric or gas range.
Wood cutting board – wood won’t dull your knives like plastic and if treated properly, has natural antimicrobial properties.
Good knife – Global is my favorite! They are worth the price, I promise. I am kind of obsessed with them and store them tucked away so no one else can use them. Including hubby. Hands off my good stuff!
Questions you might have about preparing onions:
How do I not cry when chopping onions? Well… there aren’t many ways to not cry if you are sensitive to chopping onions, but here is my video showing you the only foolproof way to not cry. Yes, I am a bit silly.
Do I have to use a sweet onion? Nope- there is a myth out there that you must use a sweet onion, also know as a Vidalia onion for caramelized onions since they are sweet. All forms of onions will lose that bite and sweeten when you caramelize (as opposed to saute) so you can use red onion, white onion, yellow onion or anything between.
Can I freeze caramelized onions? Yes! In fact I recommend it! This process takes a good amount of time, so I highly suggest making more than you think you need and freezing them in sandwich bags.
Can you make caramelized onions in the oven? You sure can. In fact, some people prefer it to having to tend to them on stove. You’ll need a good amount of heat, so set the oven to 375 degrees. Drizzle with olive oil, then bake for 30-40 minutes, stirring every once and while.
How do you make caramelized onions fast? You don’t. Those are called sauteed onions. 🙂 The chemical caramelization process of turning them to sugar takes time.
Can I use olive oil instead of butter? Yes, you can substitute olive oil for butter.
Can I omit the sugar, salt or white wine? You sure can! I like these to enhance flavor, but your caramelized onions will still taste great with any one or all of them.
What recipes use caramelized onions? Any recipe that calls for cooked onions can typically use caramelized as well. Think about any sandwich or burger. But most notably, they are used in French Onion Soup, on pizzas or in salads.
- 3 large onions thinly and uniformly sliced, ends removed
- 2 tablespoons unsalted butter
- 1 teaspoon sugar
- 1/2 teaspoon salt
- Splash of white wine only if the pan requires de-glazing
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Melt unsalted butter in large frying pan over medium-low heat. Remember, slow and steady wins this race.
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Add onions, toss to coat lightly in melted butter. Now you wait. Continue heat at medium-low, toss every 5-10 minutes. If nothing is happened, increase heat slightly. If they are cooking too fast, reduce heat. So where is what to expect:
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Onions will start to reduce. They are made mostly of water and as the water releases and evaporates, the onions will start to deflate and reduce in size.
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At around 20 minutes in you will get your first hint of the "caramel" color you are seeking.
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At 45 minutes you will have a nice brown batch of onions. Depending on your taste buds and how you intend to use them, you can stop at any point in time. Do a taste test first to make sure they are nice and sweet.
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If you've tried this recipe, come back and let us know how it was!
Recipe Video
How long do the caramelized onions last in the freezer?
HI Natalie- great question. About 3-4 months in an airtight container or plastic bag. I’ve gone longer- about 6 months, but the standard is 3-4 months.
This is an excellent set of instructions for a basic technique. Thanks for sharing.
Wishes for tasty dishes, Linda