I like it if the sauerkraut is simmering for 3 hours. I wash the kraut very well (if I can manage to get German brand sauerkraut than I don't need to wash it, it is a huge diffrence), drain. In a pot melt some goose fat (goose fat is the best, you can also use lard or sease some diced bacon). Put in the sauerkraut. Let braise a little. Add fluid. (use water, wine, champagne, broth.... ). Add carraway seeds, 1-2 bay leaves, sugar if desired. I like to add an apple (peeled and cut in small pieces). Let simmer for 3 hours an low heat. Add more water if necessary, stir once in a while. Before serving remove the bay leaves.
The carraway seeds not only taste good in the kraut they also make it better digestible.
I like my brats pan roasted and served with the sauerkraut and mashed potatoes.
Not to forget mustard and horseradish
Or the brats served with sauerkraut and slices of german farmers bread.
Depending on my dish I also like sauerkraut with pineapple and champgane and sauerkraut with apple and ginger (then I substitude part of the liquid with apple juice)