Sauerkraut is one of the simplest preserved foods, made by curing shredded cabbage with salt in a crock or jar. The drained liquid — drawn out of the cabbage by the salt through the process of osmosis — becomes the kraut’s flavorful, self-preserving brine. But there’s another process at work here, and it involves wee beasties. Bacteria.
Let’s set the record straight: Bacteria aren’t all bad. Several types of these microorganisms are very bad indeed, but others are beneficial, and necessary, to the processing of many foods. Take Lactobacillus. This bacteria is crucial to the creation of everything from pickles, yogurt and miso, to kimchi, sourdough and sauerkraut. Wine and beer? Those, too!
In the case of kraut, Lactobacillus converts the natural sugars found in cabbage to lactic acid through a process called lactic acid fermentation, or lacto-fermentation for short. This conversion ultimately imparts the appealingly acidic flavor we associate with sauerkraut. Furthermore, lactic acid is a natural preservative that prevents growth of more harmful bacteria — particularly important historically when fresh ingredients were scarce and refrigeration was a thing of the future.
Through the years the art of preservation persisted, more to satisfy our tastes than as a means of nourishment during the lean winter months. Though popularity has come in spurts and stops, sauerkraut and other fermented foods once again have a strong pulse. Encouraged by my German heritage, it felt about time to try my hand at homemade sauerkraut.