Preheat oven to 425°F.
Drizzle 2 tablespoons oil on a large rimmed baking sheet. Place 6 beets on the prepared pan and turn to coat in the oil. Cover the pan tightly with foil. Roast the beets until they are easily pierced with a fork, 50 to 60 minutes.
Meanwhile, combine ½ cup sour cream, 2 tablespoons lemon juice, ½ teaspoon sugar, ¼ teaspoon salt (if using) and ¼ teaspoon caraway seeds in a large bowl.
When the beets are cool enough to handle, peel the skins off. Grate the cooked beets with the coarsest side of a box grater and add to the sour cream mixture. Add ½ cup grated apple and mix until combined. Refrigerate for an hour to let the flavors set. Serve cold or at room temperature.
