Caramelized onions are onions that have been cooked over a low, slow heat until they are soft and browned. During this process the natural sugar in the onion caramelizes and creates a complex, delicious flavor. 

How to make caramelized onions 

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. Add the onions and cook, stirring occasionally, until the onions are a deep ,golden brown and soft all the way through. Some recipes may suggest adding extra sugar or baking soda to speed up the caramelization–don’t. These ingredients won’t speed up the process, but they will affect the flavor of your finished dish. 

How long does it take to caramelize onions

Caramelizing onions takes at least 30 minutes. This delicate process can’t be rushed. Cooking over higher heat yields onions that are crispy and charred on the outside, but still raw and spicy on the inside. Caramelizing requires slow even heat so that the onions give up their moisture and brown all the way through. 

What’s the best type of onion to caramelize 

White, yellow, red onions, and shallots can all be caramelized. Follow your recipe for the best suggestion for your dish, or slice up a mixture and caramelize them all at once. 

How to use caramelized onions

Caramelized onions can be a great addition to many recipes. Try adding them to a sandwich or a burger for a powerful kick of flavor, or use them as a pizza topping. These are some of our favorite recipes with caramelized onions.

Recipes with caramelized onions

Caramelized Onion Grilled Cheese with Butter Lettuce Salad & Creamy Fig Dressing

By filling slices of warm, golden brown sourdough bread with layers of onion and melty fontina and cheddar cheeses, we’re giving this comfort food favorite a gourmet boost. 

Caramelized Onion Grilled Cheese with Butter Lettuce Salad & Creamy Fig Dressing


Caramelized Onion & Gouda Burgers with Creamy Mustard-Dressed Corn on the Cob

To make a deliciously rich topping for beef patties (which feature smoky gouda cheese mixed right inside) we’re caramelizing onion with Worcestershire sauce and a touch of hot sauce for flavorful contrast

Caramelized Onion & Gouda Burgers with Creamy Mustard-Dressed Corn on the Cob

Three-Cheese Pizza with Caramelized Onion

A combination of fontina, Grana Padano, and fresh mozzarella cheese melt together over a flavorful tomato sauce to create this irresistible pizza. 

Three-Cheese Pizza with Caramelized Onion

Find more recipes like these on the Blue Apron cookbook.