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.

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.

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.

So using baking soda will speed up the process. But you have to be careful. If you add too much, it will impact the flavor. Different recipes recommend anywhere from ⅛ to ¼ teaspoon per pound of onions (aka about 3 large onions).

The first phase of the process is softening the onions so that they collapse into a tender mass while releasing a good deal of their liquid. If you cover the pan, you'll trap steam, which will speed up their softening, heat them more quickly, and help release their liquid more quickly.

No! Onions already contain natural sugars, which is why they're so perfect for caramelizing. This process brings out those sugars to make them more prominent. Adding more sugar would make them too sweet and mess with the flavor.

When you add baking soda during cooking it changes the pH which increases the Maillard reaction causing the onions to brown more quickly. The higher pH also causes the onions to soften more quickly, which we cover below when we discuss the texture.

Fold onions with a spatula, scraping bottom of pan to ensure they don't stick or scorch. Cook, stirring every 5 to 6 minutes and reducing heat as necessary to maintain a gentle simmer, until liquid has evaporated, about 35 minutes.

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.

Why are my onions burning and not caramelizing? ›

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.

Using baking soda to caramelize onions

Stir it in at the end of cooking for about 1 minute. Adding it too early will break down the onion fibers, turning them into mush.

You'll want to stir the onions every few minutes to make sure they're not burning. Once most of the moisture has burned off, you'll need to constantly stir the onions, scraping up the bottom of the pot with a silicone spatula to keep the onions from burning.

You don't need the balsamic vinegar, which is only there to add some flavour. The caramelization — the browning of the sugar in the onions — will take place just fine without the vinegar. Absolutely! You only need oil or butter or a bit of each in a frying pan.

For even cooking, and to prevent burning, it's essential to check and stir the onions every five to 10 minutes. And if you don't feel like you're quite up to the task, you can also try making caramelized onions in the slow cooker.

Instructions. Heat the oil in a large skillet over medium-high heat. Add the onions, peppers, salt and pepper. Reduce the heat to medium-low and cook, stirring frequently, until the onions are caramelized and the peppers are tender and slightly browned, 15 to 20 minutes.