Kitchen Basics: 5 Steps to Perfect Caramelized Onions


Savory, sweet and brimming with umami goodness, caramelized onions might be the world’s most perfect condiment.  They bring a rich depth of flavor to just about everything, from appetizers to burgers to tarts.  And, let’s be honest, food just seems a bit more classy topped with those golden tendrils. Don’t be intimidated; with just a few simple ingredients – onions, butter, oil, and patience – you can make perfect caramelized onions every time.

  1. The Slice is Right

Begin by peeling and halving your onions. Yellow onions are my go-to for caramelizing, but white or Spanish will also work. With the cut side down, go around the onion with your knife to cut slices between 1/8 and 1/4-inch thick. You might be tempted to slice them thinner to speed up the process - don’t do it!  Anything thinner than 1/8” will likely burn and stick to your pan. 

2. Big Fat Decisions

Is butter always better? Contrary to what the French might say, I say non. It’s true that butter will impart a distinctively delicious flavor to your onions—definitely très bon—but it also has the tendency to burn. I recommend using equal parts butter and olive oil. For the softest caramelized onions (think: jam), barely cover the bottom of your pan with a thin layer of fat. Conversely, for firmer, slightly-fried-at-the-edges onions, use more. The more fat in the pan, the more the onions will fry rather than soften. 

3. Room to Groove

Probably the most common mistake when trying to caramelize onions is cramming too many in the pan. It’s true that onions will reduce greatly in size as they cook, which is precisely why they need their space. Onions are full of water, which gets released during cooking. Piling too many into the pan will result in a steamy, soggy mess. In a 12-inch skillet, caramelize no more than two medium onions at a time.

4. Low, Slow and Steady

Caramelized onions don’t get their name from their color—it’s the magic of their natural sugars actually caramelizing that makes them so special. And, like most good things, coaxing out that deliciousness takes time. Unlike sautéing or frying, which can be done at a variety of temperatures, caramelizing onions requires medium-low heat. Once your pan is going, just let the onions do their thing, even if it takes an hour (and it probably will). 

5. Deglaze: It Pays

Once your onions are almost finished, make sure none of that delicious flavor gets left behind. Some of it will be hiding in the brown bits stuck to the bottom of the pan, known as sucs. Choose a liquid that will enhance the flavor of your finished dish – stock, wine, beer, vinegar, or even water – and pour a few tablespoons into the pan. Using a wooden spoon, scrape up any stuck bits and gently stir to incorporate them into the onions.

Remember: Perfectly caramelized onions take time. Your kitchen will start to smell heavenly right away, but don’t give in to temptation. Wait until your onions are soft but not mushy with a rich brown color for a show-stopping onion topping every time.