Pour a few tablespoons of sauerkraut juice into your dishes to boost healthy gut flora,  vitamins, and nutrients. Sauerkraut juice can be served on its own, in a salad dressing, as a sour seasoning, or within a dip. The juice is prepared through natural fermentation at room temperature and ready in approximately 5 days, once the juice smells sour. Learn how to make sauerkraut juice by following these steps: