In theory, cream of mushroom soup should be a delicious manifestation of its namesake: deep, woodsy, mushroomy flavor with a creamy texture.
Element of Distress
Cream of mushroom soup is most often associated with the pasty, flavorless glop in the iconic red and white can. Suffice it to say, we don’t remember it fondly.
Line of Attack
By cranking up the mushroom volume (to an impressive 3 pounds of fungi) and finessing the soup with leeks and Madeira, we’d be hot on the trail of an ultimate creamy mushroom soup.
The bar was set pretty darn low: Canned cream of mushroom soup is, to be perfectly honest, loathsome. But we started with the basic blueprint of decent from-scratch soup: sautéed onions and mushrooms, a sprinkle of flour to thicken, the addition of broth, a whirr in the blender, then a cream-y finish.
However, at first blush every batch seemed thin and wan, and the mushrooms had cooked down so dramatically, so we decided to double the mushrooms for our recipe. (Dramatic times call for dramatic measures.) It was a huge improvement, but since mushrooms are 90% water, it was important to take the time (about 15 minutes) for all of their water to evaporate and for their bits to brown and concentrate.
Aside from mushrooms, we needed a strong cast of supporting (flavor) characters. A bit of Madeira (dry sherry and brandy are also delicious) lent complexity, as did giving the butter a chance to brown slightly before sautéing the mushrooms. Garlic and thyme rounded out the flavor. To accentuate the meatiness of the mushrooms, we used beef broth and toned back on the cream.
We could see the finish line—but how could we score a silky texture for our ultra-slurpable soup? The addition of leeks (inspiration: potato-leek soup) lent the exquisite, velvety consistency we were looking for.
Creamy mushroom soup as it was meant to be: silky, earthy, and definitely uncanned.