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

FAQs

Which onions are best for caramelized 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.

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: 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.

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.

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.

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.

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.

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.

You definitely want the flavor of butter in your onions—but butter has the tendency to burn. For insurance, use a combination of butter and oil, which has a higher smoking point. But how much do you use? Depending on the consistency you want your onions, you can use more or less fat.

Why are my caramelized onions bitter? It's likely you are cooking them too fast/on too high a heat, which results in burned, not caramalized, onions. The trick to caramelizing onions is low heat and slow cooking. It can take a while, especially if you start with a big batch.

Why are my onions not caramelizing? ›

Not cooking the onions long enough.

→ Follow this tip: Cook times will vary depending on the number of onions you're cooking and the type of onion (its sugar content and age), but plan to cook caramelized onions for 40 to 50 minutes (at least) until they have a dark-brown, rich color.

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.

You can caramelize your onion in a little bit of olive oil or plant butter, whatever rocks your taste buds but olive oil is better!

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. Apparently you can make them with honey. Onions caramelize because they contain sugar.

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.

Usually caramelized onions start with thinly sliced onions, but you can also work with diced or chopped onions. To caramelize, just place a heavy pan over medium low heat and heat up some butter or olive oil.