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

FAQs

What is the secret to caramelize onions? ›

While you can start the cooking process at medium heat, low and slow is the name of the game when it comes to caramelizing onions. Once your onions begin to soften and take on a golden hue, you'll want to reduce the heat from medium to medium-low or even low for the remainder of the cooking process.

Tip: use apple cider vinegar for white and yellow onions and balsamic vinegar for red onions. Tip: the vinegar serves to deglaze the pan, adds acidity, and brings this recipe together by boosting the tangy and savory flavors of the caramelized onions. If the onions stick to the pan, that's fine.

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.

Around 30 Minutes: Onions should be light blonde in color and starting to become jammy. More fond is starting to build up, but it should still be fairly easy to scrape it up with the evaporating liquid from the onions. Around 40 Minutes: Onions are golden and starting to smell very caramelized.

You don't have to cover the pan if you don't want to, it merely shaves some minutes off the total cooking time.

In addition to water, we have another secret ingredient: baking soda. We often turn to it to speed browning, since it creates a high-pH environment, which allows caramelization to occur more readily. Baking soda is also handy for softening vegetables because altering the pH helps weaken their cell structure.

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.

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.

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.

Salting caramelized onions is like the icing on the cake. They must have salt but don't make the mistake of salting the onions too early. Instead, salt them at the very end of the recipe. Salt makes the onions release moisture which can slow down the caramelization.

Why are my onions not caramelizing? ›

It's possible that you aren't adding enough fat to the pan at first, and that your onions are sticking. That could be a problem, too. If you're way overly cautious and the flame is very, very low, it could also take a lot longer than 90 minutes, though the flavor will probably also be terrific.

When you add baking soda, the onions start to turn to mush as they caramelize. Delicious mush. But something closer to jam.

How To Make Caramelized Onions. You don't need to stir constantly, but you should be in the kitchen near the stove to monitor the onions' progress, stir, and adjust the heat as needed. Be sure to scrape down the sides and bottom of the pan frequently where the pan is hottest as small bits tend to burn in these places.

For most of the cooking process, the heat should be low or medium-low to prevent the onions from burning before they have a chance to soften and caramelize.

You don't want to slice them too thin or they'll cook too fast which could cause them to burn. You'll also want to start out with fat. I choose oil and butter. Butter gives it a good flavor and helps with the caramelization and the oil helps the butter not to brown too fast.