Basically, fermenting is a process where the starches and sugars in food are converted into lactic acid by the bacteria lactobacilli. This process gives the foods their unique sour smell and flavor and makes them nutritive super foods.
Sauerkraut is prepared by a process called fermentation. Years ago, ceramic crocks were used to ferment the cabbage. Today, most people use Ball or Kerr glass jars. Raw cabbage is shredded, pounded to release juices, and placed in a jar with salt and left to allow the acid-producing bacteria to do the fermenting. Yes, I said bacteria, but these bacteria, found on nearly everything are friendly, meaning they aren’t harmful to humans and they play a key role in the fermentation process.
In the case of sauerkraut, the bacteria is lactobacillus which you may recognize as one of the digestive enzymes. The process of making sauerkraut and other fermented foods is simple and easy and the taste of homemade sauerkraut is quite different from store bought. Salt added to the cabbage draws liquid out of the cabbage. The cabbage is submerged in its own brine and place in a cool, dark place to ferment. If you use air-lock lids, the lids allow carbon dioxide to escape while preventing oxygen from getting back in. Glass fermentation weights keep the cabbage submerged in the brine.
Cabbage isn’t the only vegetable than can be fermented and the fermentation process can be started with salt, whey, or a starter culture. The recipe you choose will tell you which to use as it may depend on which vegetable you are preserving. Kimchi is the Korean version of sauerkraut. Carrot sticks, radishes, garlic cloves, broccoli, beets and cauliflower are also good candidates for preserving by the fermentation method.
When the process is completed, vegetables should be stored in the refrigerator. If you want to keep them longer, they can be processed in a water bath canner and stored on a shelf.
For more information and recipes to try go to http://www.culturesforhealth.com/learn/natural-fermentation/how-to-ferment-vegetables/