CHILLED BEET SOUP WITH SOUR CREAM

Steps:

• Bring beets and water to a boil in an 8-quart pot, covered, then reduce heat slightly and cook at a low boil until tender, 30 to 40 minutes. Transfer beets with a slotted spoon to a bowl, reserving liquid in pot. Add carrots, cabbage, celery root, bay leaf, dill sprigs, salt, and pepper to liquid in pot and briskly simmer, partially covered, over moderate heat until vegetables are tender, about 30 minutes. Add vinegar and sugar, stirring until sugar is dissolved, then pour soup through a sieve lined with a dampened paper towel or cheesecloth into a large bowl, discarding solids (you will have about 7 cups broth; if you have less, add enough water to bring total to 7 cups).
• While vegetables cook, peel beets and coarsely grate using large holes of a box grater.
• Slowly whisk 1 cup broth into sour cream in a bowl until blended, then add to soup along with grated beets, chives, and chopped dill. Cool soup completely, uncovered, then chill, covered, until cold, at least 2 hours. Season with salt and pepper before serving.