Peel and grate the beets in a food processor. Peel and dice all other veg. Place the potatoes in a bowl of water to keep them from browning while you start the soup.
Heat 3 Tbsp. olive oil in a soup pan. Add the grated beets and 1 tsp. salt. Cook down for 5 minutes, stirring occasionally.
Add all other veg, except the garlic and potatoes. Cook another 10 minutes, stirring occasionally.
Add 1 Tbsp. butter, the potato and garlic. Stir to combine well and simmer another 5 minutes.
Add the bay leaf, beet juice, chicken stock, and water. Bring to a boil. Reduce heat. Cover and simmer for 1 1/2 hours.
Check for seasoning. Add 1/8 tsp. white pepper and add more salt if needed. Add 1/4 cup Greek style plain yogurt and 1 Tbsp. white wine vinegar.
Remove from the heat and cool completely. Blend until very smooth.
Serve either warm, room temperature or icy cold with a dollop of yogurt or sour cream and fresh chopped dill.