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Cooking Tips

Boost Your Caramelized Onions with Brown Sugar

It speeds up the process and deepens that caramelly flavor.

Caramelized onions’ concentrated flavor and tender, golden threads are delicious on, well, anything. But if you’ve ever attempted traditional caramelized onions on the stovetop, you know the process can take more than an hour. Plus, you have to keep an eye on them (burnt and caramelized are not the same things). 

Over the years, we’ve found a couple of ways to make the process easier and faster. Our mostly hands-off Best French Onion Soup recipe uses the oven. Our Quicker Caramelized Onions recipe calls for a touch of baking soda to speed up the browning and coax out the onions’ sweetness.

We now have another tip to add to the list: add a little bit of brown sugar.

Notes From the Test Kitchen

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For our new book The Savory Baker, our test cooks found that adding a teaspoon of brown sugar at the beginning of cooking enhanced the onions’ natural sweetness and helped the onions caramelize more quickly. These caramelized onions were the perfect topping for the book’s Caramelized Onion Flatbread with Blue Cheese and Walnuts recipe.

The other key was heat level. Instead of low and slow the whole way, starting the onions over medium-low heat encouraged them to release their excess moisture. Once they were slightly broken down, turning up the heat helped with deep browning (hello, flavor). This takes about 10 minutes instead of the typical 15 to 20.

How to Caramelize Onions with Brown Sugar

  1. Halve 2 pounds of onions and slice ¼ inch thick through the root end.
  2. Heat 2 tablespoons of oil in a 12-inch nonstick skillet over medium-low heat until shimmering. 
  3. Stir in onions, 1 teaspoon packed brown sugar, and ½ teaspoon salt. 
  4. Cover and cook, stirring occasionally, until onions are softened and have released their juices, about 10 minutes. 
  5. Remove lid; increase heat to medium-high; and continue to cook, stirring often, until onions are deeply browned, 10 to 15 minutes.

This method works with pearl onions, too! In our Chicken with Caramelized Pearl Onions and Almonds, a mere 5 minutes in the microwave is enough to parcook frozen pearl onions that then caramelize in 5 minutes with the help of brown sugar. 

Caramelized onions can be refrigerated for up to 3 days or frozen for up to 1 month. But with options like Caramelized Onion Jam, we doubt they’ll last that long. 

Use your caramelized onions for more with these six recipes, among our all-time favorites. Start a free trial to access all these, plus our other home kitchen–tested, foolproof recipes.