How long should saurkraut ferment?

Question

If it's allowed to ferment too long, will it go bad? When does it have the best flavor?

Answer 1

fermentation takes approx. 4-6 weeks. As far as I understood from various sources the fermentation simply stops. It is important to get all the air out so it cannot rot and absolut cleanliness is a must. It is often described that room temperature at the beginning (20° C) helps to start fermentation. After that starting period cooler temperatures are necessary.
When fermentation is finished it will have the best flavor and it can be stored for quite a while without further treatment. American Sauerkraut recipies sometimes show quite a large amount of salt being used while tradition recipies use less salt (0.6% - 2%) so that the Sauerkraut can be eaten without rinsing it before. Rinsing will wash away the salt, part of the nutrients and the flavor. Adding more salt than traditional will make temperature control less critical.

Answer 2

To be safe, do not eat any sauerkraut that has a slimy or excessively soft texture, or a discoloration or off-flavor, any of which can indicate spoilage.
5 weeks should provide excellent fermentation