Why You Should Add Baking Soda to Onions When Cooking

My family is big on Kenji’s channa masala. With staple ingredients like canned chickpeas and tomatoes, ginger, garlic, and a few basic spices, it doesn’t take long to put together, so it’s an easy way to get a flavorful dinner on the table, especially on a weeknight. And while it’s a super simple recipe, the dish is never good unless I make it—or so my family says—so I’m tasked with channa masala-ing at least once a month. The beauty of this monthly ritual is that I’ve zeroed in on one technique that really cuts down on cooking time: adding baking soda to speed up the process of browning onions. It’s such an impactful tip that I’ve started using it in other dishes, and it saves me about five to ten minutes, cutting the onion cooking time almost in half. Here’s how. 

What Happens When You Add Baking Soda to Onions

PH has a big impact on the Maillard reaction, a chemical process that encourages browning in foods when they are heated. The higher the pH, the faster the reaction occurs. Onions are only at a pH level of around 5 out of 14, making them a more acidic ingredient, but an alkaline ingredient like baking soda can increase the pH level of onions, encouraging browning in a shorter amount of time. 

Baking soda also softens onions; its high pH level, which ranges from 8.3 to 9, weakens the pectins in the vegetables, causing their cell walls to break down. The faster the onions break down, the faster chemicals are released, which means not only faster cooking, but also faster flavor and color development. 

How to Add Baking Soda to Your Onions to Speed Browning

Incorporating baking soda into your recipes to speed up onion browning is simple. Heat oil in a skillet or whatever vessel you plan to cook the onions in, then add your chopped, sliced, or diced onions, followed immediately by the baking soda. You’ll want to use about 1/4 teaspoon of baking soda per one pound of onions. Make sure the baking soda is evenly incorporated with the onions, then allow the onions to cook until beginning to brown, stirring frequently. Once the onions start to leave a brown coating on the pan, add one tablespoon of water and scrape up all the brown bits. Repeat this process until the onions are a deep brown color. The whole process should take about 10 minutes for diced onions cooked over medium-high heat, but you’ll need to adjust the time based on how finely the onions are cut.

When You Should—and Shouldn’t—Add Baking Soda to Onions

While this technique is great for quickly browning your onions, there are a few caveats. The way the baking soda breaks down the onion results in it losing a lot of its shape and taking on a softer, almost mushy texture. For a dish like channa masala or butter chicken where the onions are meant to blend in with the sauce, that’s not a problem—you wouldn’t want crunchy onions studded throughout dishes like those anyway. But when you want your onions to retain their structure in a recipe like French onion soup or Oklahoma-style onion burgers, you’ll want to skip this technique entirely, otherwise you’ll end up with gloopy onions throughout your dish. And while this tip does speed up browning time, it still takes about 10 minutes, which is why Swetha Sivakumar skips onions entirely in her 10-minute chana masala recipe. 

Baking soda also prevents onions from becoming too sweet, which, again, is warranted in certain dishes. But this hack won’t help in recipes that rely on the sweet, caramelized flavor of onions. Given the sometimes soapy notes that baking soda can give off, you’ll want to make sure the dish you’re using it in has enough flavors to mask that. 

It’s also important to note that while this technique works with white, yellow, and red onions, the baking soda does give red onions a bluish-green color that, in my experience and opinion, is not very appealing. But once the onions are incorporated with other ingredients to form a sauce, the color isn’t typically noticeable. 

The Takeaway

Adding baking soda when you’re cooking onions is a great way to speed up the browning process. However, this technique works best in recipes that don’t rely on (1) onions retaining their structure or (2) the sweet flavor of onions. But if you’re like me and want (or, really, are forced) to whip up a channa masala every month, baking soda is just what you need to save on time.