Old-Fashioned Cream of Tomato Soup

1 can (28 ounces) diced tomatoes, undrained

1 cup chicken broth

1/4 cup butter, cubed

2 Tablespoons sugar

1 Tablespoon chopped onion

1/8 teaspoon baking soda

2 cups heavy whipping cream

In a saucepan, combine the first six ingredients. Cover and simmer for 1 hour. Heat cream in the top of a double boiler over simmering water; add to the tomato mixture just before serving.