The Soaking Trick For Less Overpowering Onion Flavor

Shrek famously said that, like ogres, "Onions have layers." That's an apt observation, but what he should have pointed out is that onions ADD layers — of flavor, to any dish they're put in. That's why there are onions in so many savory recipes, from French onion soup to pasta sauce to tacos. 

Anyone who has sliced into a raw onion (or even been nearby when someone else does) knows that they have a spicy, pungent aroma and flavor that can literally make people cry. That's not a problem in recipes where onions are sautéed, fried, or exposed to heat some other way, because cooking helps mellow and sweeten the flavor of raw onions. But what can you do to tame the bite of raw onions for uncooked dishes like salads and sandwiches?

It's easy: Just give them a bath. This tip comes courtesy of "Essentials Of Classic Italian Cooking" author Marcella Hazan. Hazan's technique for mellowing raw onions consists of two or three rounds of this method: Drop the slices into a bowl of ice-cold water, squeeze the submerged slices, pour off the cloudy water, then refill with fresh, cold water. This process can last anywhere from 10-30 minutes. Pat the sliced onions dry, and now, they're mellow and ready to use.

It turns out there's more than one way to soak an onion, and they all help make onions less intense and more enjoyable in fresh dishes. One way involves vinegar: just add sliced onions to white or flavored vinegar and let them sit for about 15 minutes. Not only does this process remove the harsh, raw flavor of the onions, it also makes them more tender. Just keep in mind that vinegar will also make them taste vinegary, so pair these quick-pickled onions with foods that will love a bit of acidity, like burgers, tacos, and grain bowls. 

Another soaking technique that helps mellow out sliced onions comes from Cooks Illustrated. They recommend soaking onions in a solution of cold water and baking soda: a ratio of one tablespoon of soda for every cup of water. Conveniently this method needs no squeezing or changing of water; just let the onions sit for about 15 minutes. Cooks Illustrated explains that in addition to washing away some of the compounds that give onions their sharp flavor and aroma, the baking soda also neutralizes any compounds that remain. Rinse the onions under cold running water to wash off the baking soda, and they're ready to use: Add them to cold pasta or egg salads, scatter them atop green salads, or layer them inside a deli-style sandwich.