In a large stockpot, saute bacon until almost crisp. Drain fat. Add clam juice, onion, carrots, water, celery, and parsley. Bring to a boil, reduce heat and simmer 20 minutes.
Add potatoes and simmer 20 more minutes. At the time you add potatoes start cream sauce.
In a Dutch oven melt butter and add flour; blend until smooth. Slowly pour in cream, stirring constantly. DO NOT BOIL! When smooth, transfer to the stockpot.
Stir in clams, salt, pepper, sugar and red wine vinegar. Simmer, never let boil, until smooth and slightly thickened, about 30 to 45 minutes.
