For Faster-Browning Onions, Baking Soda Is The Key

There are few ingredients that can add as much flavor as caramelized onions. The long, slow cooking process brings out a complex mix of sweet and savory notes that are hard to match. Taking the time to make them ahead can also ensure that you have a ready supply to serve as your secret ingredient in your favorite recipes. Caramelized onions can serve as a fantastic topping for breakfast sandwiches or the centerpiece to a French onion soup recipe or appear in countless other dishes.

The biggest problem with cooking these onions, though, is that they can't be rushed. Hurrying the cooking process is one of the biggest mistakes made when caramelizing onions. Getting the proper flavor and texture takes time. Some recipes call for a minimum of an hour on the stove for the onions to properly come together. This is because they need time for their structure to break down, release water, and then for the various chemical reactions to occur that create their signature flavor.

It may seem like caramelized onions aren't an option if you're in a hurry, but there's actually a simple trick that can help. With just a pinch of baking soda, caramelized onions will become your go-to addition to everyday recipes. 

Why baking soda?

Baking soda makes for an unlikely ingredient to bring out the sweetness from an ingredient; but, in this case, that's exactly how it works. The reason that it takes so long for onions to caramelize is that it takes a long time for the structure of the vegetable to break down and release all of its water before it can caramelize. If you turn up the heat to rush this process, you'll have onions with a half-cooked interior and a browned exterior.

When you add baking soda to onions, though, it speeds up the process of breaking them down. Baking soda is an alkaline substance that raises the pH balance of onions. This helps the structure break down more quickly, and also speeds up those chemical reactions that create the caramelized flavor. It has a similar effect on meat and is the secret to tender, velvety meat.

Adding just a pinch of baking soda can help take the time for caramelizing onions from an hour down to just 15 minutes.

How to make quick caramelized onions

The biggest thing to consider when using this trick is that too much baking soda will affect the flavor of your caramelized onions. Too much baking soda can easily make your caramelized onions go from complex to chemical tasting. The key to this is to keep it down to just a pinch. Most recipes recommend about ⅛ of a teaspoon per pound of onions. It doesn't sound like much, but it should be all that's needed to speed up the cooking process. Simply add the baking soda with the butter and onions to the pan at the same time and let your secret ingredient do all the work.

One drawback to this method is that it might work too well. The baking soda is so good at breaking down the onions that it can also negatively impact the texture. While caramelized onions aren't really well regarded as having a sharp bite, the baking soda can turn them into something closer to onion jelly than caramelized onions. If you're mixing your onions into a recipe with lots of other ingredients or just piling them on top of a sandwich this won't matter much. If you want points for presentation, though, you might have to bite the bullet and slow things down instead.