Raw onions are a polarizing ingredient. I can see why. Their tangy flavor can overwhelm any dish and linger in your mouth for hours. That said, sometimes a touch of heat and crunch is just what I need in a cucumber salad or veggie sandwich. And now that we're in the middle of summer, I find myself adding thinly sliced onions to pasta salads, easy wraps, and grilled burgers.
If you're not a fan and choose to avoid raw onions for fear of the never-ending dragon breath, try this simple trick to tame its punch and mellow its flavor.
Simple Recipes / Nick Evans
The trick to making onions bite
In culinary school, I was taught to soak onions and other alliums like shallots in an ice bath (a bowl filled with water and ice) for 10 to 20 minutes to soften the flavor and crisp up the texture. After soaking, the onions are drained.
At the time, I never questioned the advice of my cooking teacher (yes, chef!) and never thought about why and how this trick worked. Like most things I learned in culinary school, it became an integral part of my daily cooking practice.
At a recent barbecue, I brought a summer panzanella and a former raw onion hater in attendance asked me how I managed to use so much without overwhelming everything else.
I happily explained the simple trick I had learned years ago, but I wasn’t prepared for what came next: “But how?” Great question. I wanted to answer, “Because the boss said so,” but that didn’t seem appropriate for someone in their late 40s. Not being able to answer that question hurt, so I decided to find out.
Simple Recipes / Mark Beahm
Why Soaking Onions in Cold Water Works
A quick search revealed that onions and alliums are high in sulfur: they grow in the ground and absorb sulfur from the soil. These sulfur compounds are responsible for the tears we feel when we cut onions, as well as their strong flavor.
When onions are sliced, these sulfuric enzymes are released and remain on the surface of the onion. When you soak them in cold water, two things happen. The water rinses away the enzymes and the cold temperature makes them less reactive. This is why some suggest freezing an onion for a few minutes before slicing it to reduce tears.
Other methods that work
An ice bath is best if you want crispy onions, but if you don't mind a softer texture, vinegar or lemon juice work. If I'm making a pasta salad, I usually soak the onions in the dressing without the extra step of making an ice bath and draining them. The folks at Milk Street suggests salting the onions, which breaks down the fibrous texture and mellows the flavor.