My Grandmother gave me a cookbook, "German Cooking" by Arne Kruger years ago. She has been gone some years now. She loved this recipe; while cooking she would eat pickled pigs feet and drink a Pilsner. Not bad, considering she was in her late 80's then. This 4'10" tall little old lady, eating those pigs feet

My Mom LOVES this recipe! I add more carrot, couple more peppercorns. I also add some garlic.
Rheinischer Sauerbraten:
2 cups vinegar
2 cups water
4 onions, sliced
1 stalk celery, chopped
1 carrot, shopped
2 bay leaves
8 pepper corns, crushed
8 whole cloves
1/4 teaspoon mustard seed
1 (4-5lb) rump roast of beef
1 teaspoon salt
1/4 teaspoon pepper
1/4 cup salad oil
4 Tablespoons flour
1/2 cup seedless raisin
1/2 cup sour-cream
Combine vinegar, water, onions, celery, carrot, bay leaves, peppercorns, cloves, and mustard-seed in saucepan. Bring to a boil; cool.
Place meat in a large bowl. Pour marinade over meat. Place in refrigerator and marinate for 2-3 days, turning several times
Remove meat from marinade; dry well. Sprinkle meat with salt and pepper. Heat oil in a Dutch oven. Brown meat very well on all sides.Add 2 cups of the marinade; cover, and simmer 2-3 hours till meat is very tender. Remove meat; keep warm.
Strain sauce; skim off fat and measure liquid. Add water or marinade to make 2 cups. Stir in flour. Return to pan. Cook over low heat, stirring and scraping brown bits, until thickened. Stir in raisins and sour cream. Blend well. Serve with meat.