1. Heat oil in large pot. Add onion, celery, and parsnips. Sauté 10 minutes.
2. Stir in wine or apple juice, scraping bottom of pot to loosen brown pieces. Add water, salt, pepper, potatoes and bay leaf.
3. Bring to a boil; reduce heat to medium. Cook 20 minutes or until vegetables are tender. Discard bay leaf.
4. Blend with immersion blender until smooth. Stir in lemon juice. Pour into bowls. Swirl in sour cream, if desired. Sprinkle with parsley.