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

FAQs

What is the secret to caramelize onions? ›

Choose Your Onions

I usually use yellow onions, but white or purple will also work. The amount of onions to caramelize is up to you. I find that two to three work well for a large skillet. Keep in mind that the onions will cook down quite a lot and leftovers refrigerate well.

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.

If the onions aren't deeply brown after 50 minutes and you'd like to speed things up, you can turn the heat higher to get more caramelization. Stir continuously to prevent burning.

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.

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.

Like I mentioned above, we want to get rid of all the water in the onions to allow for browning to take place. But once the onions do start to brown, water can be your best friend! Adding water periodically into the pan while caramelizing your onions will prevent burning.

Unlike mushrooms, which shouldn't be salted until after they've browned, you should always salt onions before you start cooking them. Onions won't begin to caramelize until all the water in them has evaporated, and using salt will speed up that process, Caicedo explains.

Do you caramelize onions on low or high heat? ›

The key to making Caramelized Onions is cooking them low and slow. No more than medium heat and plan for it to take awhile. I always make a large batch for 2 reasons. One: they cook down to a much smaller amount than the raw onions.

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.

Onions contain sugar which is what caramelises when you cook them. You do not need balsamic vinegar. You just have to cook the onions for a long time on a low heat. It can take up to 20 minutes to get the right colour.

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.

The baking soda speeds up the Maillard reaction

According to cookbook author and food writer Kenji López-Alt, you can speed up the process of caramelizing onions by adding a pinch of baking soda (via Serious Eats).

Brown sugar is simply cane sugar with molasses added to it. Therefore, you are adding even MORE sugar, and more brown color, to your onions. Thus the caramelization is so much better and faster! If you don't have brown sugar, feel free to use regular cane sugar or even panela when caramelising onions.

Unlike mushrooms, which shouldn't be salted until after they've browned, you should always salt onions before you start cooking them. Onions won't begin to caramelize until all the water in them has evaporated, and using salt will speed up that process, Caicedo explains.

If your heat is too high, the onions will burn. Heat your pan over medium-low, then add your onions. Keep it on that temp for the whole process. No cheating!