Balsamic Caramelized Onions | The Best Caramelized Onions Recipe (2024)

FAQs

Why add vinegar to caramelize onions? ›

I usually stick with balsamic vinegar because the flavor complements the onions perfectly. Not only will deglazing pull up tasty sticky bits, it will add even more flavor to your caramelized onions. Continue stirring the onions until they have reached the color you like.

Caramelize the onions: Heat about 1 tablespoon of canola oil in a large skillet or dutch oven over medium-low heat. Once hot, add the onions and stir to coat. Let cook, stirring every 5-10 minutes, until deeply caramelized, about 1 ½ - 2 hours.

Our Test Kitchen likes to use butter when caramelizing onions, as it offers the richest flavor. If you avoid dairy or don't have butter, you can caramelize onions in other fat such as margarine or olive oil. Add the onion slices. It's okay if they overlap a bit here because they'll shrink as they cook down.

Stirring the onions and scraping down the sides of the pan often to ensure no strand darkens faster than another is key. A heatproof rubber spatula is the tool for this job; it's stiff enough to scrape the bottom of the pan and flexible enough to clean the sides.

After 10 minutes, sprinkle some salt over the onions, and if you want, you can add some sugar to help with the caramelization process. (I add only about a teaspoon of sugar for 5 onions, you can add more.) One trick to keeping the onions from drying out as they cook is to add a little water to the pan.

You can use just oil, or a combination of butter and oil—the choice is yours! If you pack too many onions into your pan, they'll steam and produce water. Eventually, they will caramelize—but it will take much longer to get them there.

So adding water and covering the skillet causes the raw onions to wilt faster and more evenly as the water turns to steam. Then, uncover the skillet and begin a process of pressing the softened onions into the bottom and sides of the skillet for maximum contact—and maximum browning.

Apparently, the trick to getting onions to caramelize more quickly is to add baking soda.

Simply put, caramelized onions aren't quick. It takes at least 45 minutes (and often over an hour) over low heat for the natural sugars in the onions to caramelize. Still, the time is totally worth it. Packed with irresistible umami flavor, caramelized onions add complexity to all sorts of savory dishes.

Once the water is boiling or close to it, put a lid on the pan so the onions can steam. This essentially massively speeds up the process of wilting the onions, which can be the first 15-20 minutes of the sautéing process.

How do you know when onions are caramelized enough? ›

You'll know the onions are ready when they're deep brown in color and jammy in texture. They should also be fully translucent and completely sweet. If they're still kind of crunchy, or they still have some of that raw onion bite, let them cook for a bit longer.

Third, help things along with a little bit of sugar. In science speak, caramelization is the oxidation of sugars. Here, those sugars are the natural sugars in the onions, but the addition of a small amount of white sugar adds an extra caramelization boost.

Just make sure not to exceed the ratio of two tablespoons per two onions, as you don't want to end up frying the onions. You only need enough oil and butter to coat the bottom of the pan without fully submerging the onions.

You can caramelize any kind of onion, but yellow or Spanish onions tend to offer the most balanced-sweet-savory flavor profile and are the most versatile for different dishes. Sweet onions, such as Vidalia or Walla Walla work too, but keep in mind that their flavor will become even sweeter once caramelized.

You're not sautéing your onions—you're trying to slowly coax flavor out of them. It takes time, probably a solid 45 minutes, for the onions' sugars to caramelize. If your heat is too high, the onions will burn. Heat your pan over medium-low, then add your onions.

The more fat you use the more charred and fried they will be. If you like them more charred then by all means add more fat! Once your butter is melted and oil is heated then add your onions. Stir often so that they can sweat out all the moisture before they start to brown.

The best type of pan for caramelizing onions is a wide, thick-bottomed cast iron or stainless steel pan. Although onions can also be caramelized with alternative cooking methods and containers, like a crock pot or slow cooker, nothing beats a sturdy sauté pan.