Blend Caramelized Onions Into Soups for Extra Umami

The Northern Hemisphere is going into soup mode right now, but soup itself has (at least) two modes: brothy, with stuff bopping around in it, and blended, with the ingredients pulverized into creamy oblivion. Both have the power to warm from within, but pureed soups pack tons of flavor into a single spoonful—and you can pack even more in with caramelized onions.

Caramelized onions in soup are nothing new—hello, French onion—but this recipe from Food52 was the first time I can recall seeing them pureed. Much like blending burnt onions into ranch dressing or turkey gravy, caramelized onions add a deeper, roastier flavor your soup might otherwise be lacking. Unlike burnt onions, caramelized onions are sweeter, jammier, and not nearly as bitter.

Blending caramelized onions into a soup—like tomato, potato, or even a chowder—sweetens and thickens it, while making it taste more “finished.” Caramelized onions don’t just taste like onions, they taste like time well spent, like someone put some effort in developing all of those sweet and umami-packed flavors.

You do not, however, have to put in much effort at all. Though caramelizing onion takes a little longer than most recipe writers will have you believe, that time can be mostly hands off if you move the onions from the stovetop to the oven. Aim for one or two onions per pot of soup, though I think it’s hard to overdo it here. Also, don’t feel beholden to one allium; caramelized shallots, leeks, and garlic can also be blended right into your soup of choice to excellent results.

Once your onions are caramelized (either on the stove or in the oven), all you have to do is slip them into a soup and puree them in a high-powered blender, or stick an immersion blender down into the pot. (Though I prefer a standard high-powered blender here; it makes a creamier soup.) Sprinkle on some dehydrated caramelized onions to finish. It may be lily gilding, but that’s OK when the lily is an onion.