The Science-Backed Way to Caramelize Onions in Half the Time

I always joke that if I could make a custom Yankee Candle, it'd be sautéed onion-scented. It may sound odd, but in my opinion, there are few smells more enticing than that of onions (and garlic while we're at it) cooking down. For most of my childhood, that meant something was happening in the kitchen, and something good at that.

These days when I cook for myself, I don't do the traditional meal prep, but I do like to prepare some components to help me iterate on lunches and dinners throughout the week. One of the most frequent things I do is make a big batch of caramelized onions for two reasons. The first is that everything is better with caramelized onions; chicken, burgers, dip, quesadillas—you name it.

The second reason is that truly caramelized onions take a long, long time. Luckily, I found a hack that cuts the time down by half and even makes them weeknight-friendly, meaning you have a delicious, cheap dinner upgrade in your back pocket any time you need it.

How to Caramelize Onions Fast

Caramelizing onions can be a painstaking process that, if done the right way, can take well over an hour, even if you use a hands-off method like the slow cooker. To understand why, let's get into a quick science lesson.

Onions (like all vegetables) have lots of naturally occurring sugars, and cooking over heat draws out those sugars alongside amino acids to caramelize them, which is what causes the onions to take on a darker brown color and sweeter flavor. Cook onions too little, and they won't have enough time to develop that sweetness; cook them too hot and those sugars can burn. However, there's one simple step you can take that will not only speed up the process but make it more fool-proof, too.

I first learned this tip from Cooks Illustrated, and have been using it regularly since. Typically, you start with a pan, then add butter or oil and your onions and sauté on low heat until they start to cook down, stirring constantly. In this method, you add the onions to a skillet (preferably nonstick) with a little oil and salt and notably, water. About 1/2 cup is good for a big batch of onions. 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. And what's more, the water at the bottom becomes infused with all the sugary onion juices, distributing those sugars evenly through the onions. The resulting onions are softened in a matter of minutes, leading to caramelized onions in a few more.

You can also use vegetable, chicken, or beef broth in place of water for extra flavor. Adding the liquid gives you more leeway to walk away from the pan for a minute or two and not worry about whether the onions are going to burn. However, if at any point the pan does look dry, add a little more water (or broth or a splash of wine) to deglaze the pan, and keep stirring. Once the onions are softened and starting to brown, stir continuously until you reach your desired browning.

You can watch the full technique here, but really, just following this one step of liquid at the start of the cooking process will drastically reduce the total time.

This is one of those tips that will truly change the way you cook. Even if you don't want to take your onions to a stage of deep caramelization, it will cut down the prep time for any onion and make your weeknights *that* much faster and easier.