How to Caramelize Onions

How to Caramelize Onions

Caramelized onions are sweet onions that have been cooked low and slow to caramelize their natural sugars. They're both savory and sweet and have the most wonderfully complex flavor.

Course Ingredient

Cuisine American, French

Diet Gluten Free, Vegetarian

Prep Time 5

Cook Time 1 20

Total Time 1 25

Servings cup

Calories 103kcal

Author Kyleigh Sage

Equipment

Ingredients

4 large sweet onions
4 tablespoons unsalted butter
½ teaspoon kosher salt
1 teaspoon fresh thyme optional

US Customary - Metric

Instructions

Caramelizing onions takes a long time (but it's SO worth it for the flavor), so I like to make the caramelized onions a day in advance of whatever recipe I want to use them in.
Thinly slice the onions.
Melt the butter in a large stainless steel or cast iron pan over medium low heat.
Add in the onions and season with salt. Cook slowly over low heat, until deep golden brown and caramelized, about 1 to 1 ½ hours. Be sure to stir occasionally (every 10 minutes or so), so that the onions don't burn.
After about 20 minutes the onions should be slightly softened but still colorless. After 40 minutes the onions should be soft and just beginning to brown. At 1 hour the onions should be lightly caramelized; you can stop at this point but I like to let them cook for another 20-30 minutes. After about 1 ½ hours, the onions should have a jammy consistency and be a deep golden brown color with a sweet flavor.
Add in the fresh thyme and deglaze the pan with about 1 tablespoon of water, making sure to scrape up all the browned bits on the bottom of the pan. Let cook for another minute or two to let the water evaporate. Instead of water you can also deglaze the pan with apple cider vinegar for a little bit of acidity.
Remove from the heat and enjoy!

Notes

1 large onion = about 2 cups when sliced which then yields about ¼ cup of caramelized onions. So you can scale the recipe as needed!

Store in an airtight container in the fridge for up to 5 days.

Nutrition