Sauerkraut was created as a way to put up extra cabbage for storage throughout the winter, when other produce is scarce. The fermented cabbage in homemade sauerkraut boasts high levels of vitamin C, is more digestible than fresh cabbage and helps you better digest other foods. On top of all those benefits is probably the best one of all -- it lasts a really long time when refrigerated under optimal conditions.
Homemade, fermented sauerkraut can last for months in the refrigerator with no ill effects. Commercially sold sauerkraut will stay fresh for months if left unopened, but once you open and use some of it, the rest will only stay fresh for a couple of weeks.
Fermented sauerkraut is a pickled food, so it keeps very well under optimal storage conditions and can last for several months in the refrigerator. To store sauerkraut for extended periods, ensure that the temperature of your refrigerator is set to at least 36 degrees Fahrenheit or below. Store the sauerkraut in a sealed container with a tight-fitting lid. Store commercially sold sauerkraut in the jar it came in, making sure to use it once opened within a couple of weeks.
Below the Brine Line
How sauerkraut is stored in the refrigerator affects the quality. Make sure the sauerkraut in a jar is fully immersed in the brine to prevent it from becoming oxidized because of air exposure. Push the sauerkraut below the brine level before storing it and use a clean utensil to do so each time. Metal that is exposed to sauerkraut can rust, so avoid storing the food in a jar with a metal lid.
Spoilage in fermented sauerkraut is rare when properly stored in the refrigerator. The most common change is darkened sauerkraut because of air exposure and storing it above the brine. In this case, remove the browned sauerkraut and continue eating the rest. Spoilage in commercially sold sauerkraut is more common. If you detect any off odors or other changes in your sauerkraut, such as a mold or pink scum, throw it out. In some kinds of sauerkraut, such as a wine sauerkraut, the flavors dissipate over time and it may lose some of its crunch and flavor.
When you're making sauerkraut at home, can large batches in a boiling water bath to preserve it for as long as a year. If you bought a jar or bag of sauerkraut that you cannot eat in one meal or within a few months, freezing it is another way to keep it fresh. Place the sauerkraut in a freezer bag or other freezer container to store for later use. When ready, defrost the sauerkraut in your refrigerator and use.