Cold Spinach Soup

2 pounds spinach, stemmed
¼ cup loosely packed fresh dill
1 scallion, white and light green parts trimmed and thinly sliced
½ pound good-quality dill pickles, cut in 1/4-inch dice (or substitute peeled and seeded cucumbers)
12 ounces beer
¼ teaspoon peeled, freshly grated horseradish
1 ½ cups water
Kosher salt to taste
6 bunches sorrel (about 1 1/2 pounds), stemmed and cut horizontally into 1/8-inch-wide strips (optional)
Scant 1 tablespoon unsalted butter (if adding sorrel)
½ cup sour cream (1 1/2 cups if adding sorrel)
½ cup plain yogurt (1 1/2 cups heavy cream if adding sorrel)
1 tablespoon apple-cider vinegar

Nutritional Information
- Nutritional analysis per serving (10 servings)
  79 calories; 4 grams fat; 2 grams saturated fat; 0 grams trans fat; 1 gram monounsaturated fat; 0 grams polyunsaturated fat; 6 grams carbohydrates; 2 grams dietary fiber; 1 gram sugars; 3 grams protein; 10 milligrams cholesterol; 473 milligrams sodium

8 to 12 servings

Wash spinach and place in a large skillet with the adhering water. Cover. Cook over medium heat for 10 minutes, stirring once or twice, just until wilted. Drain. Place the spinach and the dill in a food processor and process until finely chopped.
Scrape mixture into a metal bowl. Stir in scallion, pickles, beer, horseradish, water and salt.
If using sorrel, heat the butter in a large skillet over medium heat until just melted. Add the sorrel and cook 4 to 5 minutes, or until color turns. Remove from heat. Stir sorrel, 1 1/2 cups sour cream and 1 1/2 cups heavy cream into spinach mixture. If not using sorrel, stir in 1/2 cup yogurt instead of heavy cream and 1/2 cup sour cream. Refrigerate until cold. Just before serving, stir in vinegar. Add more salt if needed.

25 minutes