Drain sauerkraut, reserving juice. Add water to kraut juice to make 3 cups. In a large soup pot, bring chicken broth and kraut/water to a boil. Add carrots and potatoes, cover and cook until veggies are desired tenderness.

In a skillet, chop and brown bratwurst until it gets nice and brown.

Remove from pan, set aside.

Do not clean pan. Add onion and celery to pan, and saute for about 5 minutes.

Add sauerkraut, continue browning until sauerkraut is cooked well.

Return bratwurst to kraut mixture.

Add to broth.

In a small saucepan, melt butter, add flour to melted butter and whisk, making a roux.

Slowly add milk and cream to flour mixture.

Cook on low whisking as it thickens.

Pour into broth and let soup simmer on low until heated through.