Preheat oven to 400 degrees. If beets have tops slice off the tops as closely to the beet as possible. Wash beets thoroughly. There is no need to dry the beets. Wrap each beet in foil tightly. Place foil wrapped beets on a baking sheet. Bake for approximately 50 to minutes. Beets should be tender to the touch. When the beets cool, hold them with a paper towel. You should be able to push off the skins.
In a medium sized bowl combine sour cream, white onion, salt, sugar, and balsamic vinegar. Stir to combine sauce. Dice beets and stir into the sour cream dressing.
Store in an air tight container.