1Soak mushrooms over night in water, drain in morning.
2Chop up the mushrooms and add to 2 quarts of water along with the garlic and cook for 1/2 hour.
3Add the sauerkraut and the sauerkraut juice to the mushrooms ( if you like your soup more sour, add more juice now, if you don't have extra, use a teaspoon of white vinegar) Cook for another 1/2 hour.
4Melt the butter and saute the onions until lightly brown, now make a rue frying the flour in the butter till the flour is browned lightly.
5Add the rue to the mushrooms and sauerkraut and cook for an additional 20 minutes.