How to Make It
Combine first 8 ingredients in a large saucepan. Bring to a boil. Reduce heat, and simmer over medium-low heat until reduced to 2 1/2 cups (about 1 1/2 hours). Strain the stock through a sieve into a bowl; discard solids.
Bring the wine to a boil in pan until reduced to 1/2 cup (about 3 minutes). Combine flour and turkey drippings in a bowl, stirring with a whisk until smooth. Add to pan; cook over medium heat for 1 minute, stirring constantly. Stir in the strained stock, salt, and ground black pepper; cook over medium heat 15 minutes, stirring occasionally.