Add water and simmer on stove top uncovered 45 minutes.
Strain the stock into a bowl and refrigerate for 2 hours or even overnight. Using a spoon remove the fat accumulated on top.
Heat a large saute pan on medium high heat, add butter and let melt . Whisk in flour and cook about 30 seconds. Whisk in turkey stock and vinegar.
Bring to a boil then reduce heat and simmer until thickened. Turn off heat, sauce will thicken more once its starts to cool down.