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

FAQs

Why add vinegar to caramelize onions? ›

This is our secret ingredient to make the best caramelized onions. Vinegar adds a touch of acidity to balance out the sweetness of the onions. It elevates their flavor wonderfully. We recommend balsamic vinegar if you use red onions and apple cider vinegar if you use white or yellow onions.

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.

In a large cast iron skillet or large cast iron enamel Dutch oven over medium-low to medium heat, caramelize the onions: melt butter, add onions, season with bay, salt and black pepper and white pepper, thyme, cook to golden and soft, 25 minutes, then add sherry if using and remove to a bowl.

We then need to get the steam and the water from the onions out of there. Otherwise, the onion won't brown. Once you cook the onions with the lid on for about 20 minutes, take the lid off. That allows the water to cook off.

Combine the butter and oil in a large sauté pan over medium heat and cook until it begins to shimmer. Add the onions, toss to coat in the butter and season with salt and pepper. Cook the onions, stirring occasionally, until golden brown and caramelized, about 30 minutes.

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.

Adding baking soda makes the onions more alkaline, increasing the speed of the Maillard reaction so they brown more quickly. But it also imparts a chemical-like bitterness to the end result.

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.

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.

Not cooking the onions long enough.

It might be tempting to pull the onions off the stove as soon as they start to soften and turn golden-brown, but resist the urge. They're not completely cooked yet — they need more time. Caramelized onions should be far darker than golden in color.

How do I know when caramelized onions are done? ›

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.

Throw in cast iron pan, add a bit of fat (butter, gee, oil, anything really), and a pinch of salt. Bring pan up to medium low heat, and over the course of 60-90 minutes stir your onions and caramelise them. If onion is at risk of burning, add a splash of water and reduce the temperature a bit.

Stir Occasionally: Stir the onions every few minutes to prevent sticking and ensure even cooking. However, don't stir too often, or they won't caramelize properly. Patience is key: It can take around 30-40 minutes of regular stirring to achieve that perfect, rich caramel color.

Sautéing vs caramelizing

Sautéing is about softening and lightly flavoring the onions, while caramelizing is about developing a rich, sweet complexity. Unfortunately, you can't swap one out for the other without changing the flavor profile of your dish.

The trick is to leave them alone enough to brown (if you stir them too often, they won't brown), but not so long so that they burn. After the first 20 to 30 minutes you may want to lower the stove temperature a little, and add a little more oil, if you find the onions are verging on burning.

Cook onions too little, and they won't have enough time to develop that sweetness; cook them too hot and those sugars can burn.