America's Test Kitchen LogoCook's Country LogoCook's Illustrated LogoAmerica's Test Kitchen LogoCook's Country LogoCook's Illustrated Logo

Sweet Potato Soup

By Lan Lam

Published on September 24, 2015

Time

1 hour

Yield

Serves 4 to 6 as a main dish or 8 as a starter

Sweet Potato Soup

Ingredients

4 tablespoons unsalted butter 1 shallot, sliced thin4 sprigs fresh thyme 4 ¼ cups water 2 pounds sweet potatoes, peeled, halved lengthwise, and sliced ¼ inch thick, ¼ of peels reserved1 tablespoon packed brown sugar ½ teaspoon cider vinegar Salt and pepper Minced fresh chives

Before You Begin

To highlight the earthiness of the sweet potatoes, we incorporate a quarter of the skins into the soup. In addition to the chives, serve the soup with one of our suggested garnishes (see “More Like This”). The garnish can be prepared during step 1 while the sweet potatoes stand in the water.

Instructions

  1. Melt butter in large saucepan over medium-low heat. Add shallot and thyme and cook until shallot is softened but not browned, about 5 minutes. Add water, increase heat to high, and bring to simmer. Remove pot from heat, add sweet potatoes and reserved peels, and let stand uncovered for 20 minutes.
  2. Add sugar, vinegar, 1 1/2 teaspoons salt, and 1/4 teaspoon pepper. Bring to simmer over high heat. Reduce heat to medium-low, cover, and cook until potatoes are very soft, about 10 minutes.
  3. Discard thyme sprigs. Working in batches, process soup in blender until smooth, 45 to 60 seconds. Return soup to clean pot. Bring to simmer over medium heat, adjusting consistency if desired. Season with salt and pepper to taste. Serve, topping each portion with sprinkle of chives.

Sweet Potato Soup

Save

Time

1 hour

Yield

Serves 4 to 6 as a main dish or 8 as a starter

Ingredients

4 tablespoons unsalted butter
1 shallot, sliced thin
4 sprigs fresh thyme
4 ¼ cups water
2 pounds sweet potatoes, peeled, halved lengthwise, and sliced ¼ inch thick, ¼ of peels reserved
1 tablespoon packed brown sugar
½ teaspoon cider vinegar
Salt and pepper
Minced fresh chives

Test Kitchen Techniques

Ingredients

4 tablespoons unsalted butter
1 shallot, sliced thin
4 sprigs fresh thyme
4 ¼ cups water
2 pounds sweet potatoes, peeled, halved lengthwise, and sliced ¼ inch thick, ¼ of peels reserved
1 tablespoon packed brown sugar
½ teaspoon cider vinegar
Salt and pepper
Minced fresh chives

Test Kitchen Techniques

Ingredients

4 tablespoons unsalted butter
1 shallot, sliced thin
4 sprigs fresh thyme
4 ¼ cups water
2 pounds sweet potatoes, peeled, halved lengthwise, and sliced ¼ inch thick, ¼ of peels reserved
1 tablespoon packed brown sugar
½ teaspoon cider vinegar
Salt and pepper
Minced fresh chives

Test Kitchen Techniques

Why This Recipe Works

Most sweet potato soup recipes call for so many other ingredients that the sweet potato flavor is muted. By cutting back to just shallot, thyme, and butter and using water instead of broth, we put the focus back on the main ingredient. We also puree some of the potato skins into the soup for extra earthiness. However, the real key to intensifying the sweet potato flavor was using only a minimal amount of flavor-diluting water. To do so, we let the sweet potatoes sit in hot water off heat for 20 minutes to make use of an enzyme that reduces their starch content. Less starch meant we could create a soup with less water, keeping the sweet potato flavor in the forefront.

Before You Begin

To highlight the earthiness of the sweet potatoes, we incorporate a quarter of the skins into the soup. In addition to the chives, serve the soup with one of our suggested garnishes (see “More Like This”). The garnish can be prepared during step 1 while the sweet potatoes stand in the water.

Instructions

  1. Melt butter in large saucepan over medium-low heat. Add shallot and thyme and cook until shallot is softened but not browned, about 5 minutes. Add water, increase heat to high, and bring to simmer. Remove pot from heat, add sweet potatoes and reserved peels, and let stand uncovered for 20 minutes.
  2. Add sugar, vinegar, 1 1/2 teaspoons salt, and 1/4 teaspoon pepper. Bring to simmer over high heat. Reduce heat to medium-low, cover, and cook until potatoes are very soft, about 10 minutes.
  3. Discard thyme sprigs. Working in batches, process soup in blender until smooth, 45 to 60 seconds. Return soup to clean pot. Bring to simmer over medium heat, adjusting consistency if desired. Season with salt and pepper to taste. Serve, topping each portion with sprinkle of chives.

Gift This Recipe

Enjoyed this dish? Let others know by sharing it as a gift recipe.

This is a members' feature.