There Is Only One Secret to Caramelizing Onions (2024)

FAQs

There Is Only One Secret to Caramelizing 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.

Your heat isn't at the right temp, use between medium and medium-low. Adding too many onions at once can actually cause them to steam because of too much moisture, instead of caramelizing. Brown them first (before carmeling) by sautéing them on med to medium high using just enough fat to cover pan bottom.

When onions caramelize, one of the main things that happens is the sucrose, or natural sugar hidden within their cells, is transformed into other, simpler forms of sugar, including glucose and fructose. Those sugars taste sweeter than sucrose, which accounts for the increase in sweetness as the onions caramelize.

Vinegar. 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.

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.

Just make sure not to exceed the ratio of two tablespoons per two onions, as you don't want to end up frying the onions. You only need enough oil and butter to coat the bottom of the pan without fully submerging the 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.

So adding water and covering the skillet causes the raw onions to wilt faster and more evenly as the water turns to steam. Then, uncover the skillet and begin a process of pressing the softened onions into the bottom and sides of the skillet for maximum contact—and maximum browning.

If you need to caramelize onions quickly, adding sugar or a pinch of baking soda (to raise the pH level and help them brown quicker) can help to speed up the caramelization process but truly they aren't a dish that cooks up quickly. If using baking soda I'd suggest about 1/4 tsp per pound of raw onions.

What is the best liquid to caramelize onions in? ›

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.

Turn or stir the onions so that they evenly become soft and brown, but don't worry about exact timing. Continue stirring those onions and enjoy watching them turn from white to a delicious golden brown. As they begin to soften, reduce the heat to medium-low or low.

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.

Once the water is boiling or close to it, put a lid on the pan so the onions can steam. This essentially massively speeds up the process of wilting the onions, which can be the first 15-20 minutes of the sautéing process.

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. Sautéing onions quickly brings out their natural flavors while maintaining some brightness.

You'll know the onions are ready when they're deep brown in color and jammy in texture. They should also be fully translucent and completely sweet. If they're still kind of crunchy, or they still have some of that raw onion bite, let them cook for a bit longer.

Before onions can caramelize, enough moisture has to evaporate out of the pan for the cooking surface to climb above 212 degrees. That alone takes a while, and once it happens, you're still committed to stirring and scraping so the onions' natural sugars break down evenly.

The onions will indeed heat faster when cut really thinly, but they'll end up heating too fast for true caramelization to occur. Onions need to cook for a long time for the natural sugars to come out and for that delicate flavor to develop. If they heat up too quickly, they'll burn before that can happen.

To get crispy onions you need to deep fry it in a lot of oil. Sauteing in a shallow pan will result in softened onions as they release their juice slowly and get cooked. Don't add salt as they are frying as it will further draw the moisture out and soften the 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.