How Long Does Sauerkraut Last Once It Is Made or Opened

Homemade sauerkraut in the refrigerator

Once a homemade batch has fermented to your taste, moving it to the refrigerator slows the changes but does not stop them. Home fermenters commonly report that a jar stays good for several months when kept cold, covered by brine and handled with clean utensils. Some people keep it considerably longer, though flavor and texture shift with time.

There is no guaranteed number, so treat the timeline as an estimate. A batch made with enough salt, packed tightly and kept under the brine tends to hold up better than one made carelessly. Write the date on the lid so you can see at a glance how old the jar is.

Store-bought sauerkraut

Shelf-stable canned or jarred sauerkraut has usually been heat-treated, so it keeps unopened in the pantry for a long period, and the package carries a date. The fermentation microbes are no longer alive in these products. Refrigerated, unpasteurized sauerkraut is different: it is still alive, still slowly changing, and best kept cold.

After opening either type, keep it in the refrigerator, press the kraut under its liquid and use a clean fork. Follow the storage instructions on the label, since the maker knows the product best. If the brine level drops, you can top it up with a little salt water, which many recipes describe as about 2 percent salt by weight, to keep the cabbage covered.

What normal aging looks like

Sauerkraut gets more sour over time, and its color moves from bright, pale green toward a darker, more yellow tone. The shreds soften and the brine can turn cloudy. Those changes are normal and do not signal spoilage. Some sediment on the bottom of the jar is also usual, since it is made up of dead yeast and bacterial cells.

A faint fizz when you open the jar is the product of continuing fermentation. If your kraut has become more sour than you like, rinse it briefly before eating, or cook it into a dish such as braised pork or potatoes, where the acid becomes part of the flavor. You can also put the jar in a colder part of the fridge to slow things down.

Signs sauerkraut has spoiled

Mold is the clearest warning. It appears as fuzzy or dry patches in white, green, blue, black or pink on the surface. If you see it, discard the jar, because you cannot reliably remove contaminated portions. A smooth, flat white film on the brine surface can be harmless kahm yeast, which you can read about on our page about avoiding mold and kahm yeast, but when you are unsure, discarding is the safer choice.

Also watch for a smell that is putrid or rotten, rather than sharp and sour, and for slimy shreds that feel mushy in a way that goes beyond softness. Do not taste suspicious food to find out. Official food safety advice generally says to throw out any ferment you think has spoiled.

Habits that make a jar last longer

The most useful habit is keeping the cabbage under the brine. Exposed pieces are where surface growth begins. A fermentation weight or a folded cabbage leaf pressed on top can help hold everything down. In the refrigerator, a tight lid also limits contact with air and fridge odors.

Use a clean utensil every time, and avoid putting used forks back in the jar. Store the jar at the back of the fridge where the temperature is steadier than in the door. If you make large batches, split them into several smaller jars and open one at a time, which limits how often each jar is exposed to air and handling.

Compare fermented food storage containers →

Freezing and canning questions

Freezing sauerkraut is possible, and it softens the texture a little. It is a way to pause a big batch, though the live cultures may be reduced. Leave headspace in the container to allow for expansion, and thaw it in the refrigerator before use.

Canning sauerkraut at home involves heat, which kills the live bacteria and requires following tested procedures from a reliable source, such as a national extension service, to stay safe. Do not improvise with canning times or jars. If you simply want to keep a ferment for a long time, refrigeration is the simpler route.

Choosing the right container

A jar with a tight lid is the simplest option for refrigerator storage. Glass does not absorb odors or stain, and you can see the brine level at a glance. Wide-mouth jars are easier to fill and to reach into with a fork, while narrow ones make it harder to keep the cabbage submerged.

Whatever you choose, make sure it is clean and food-safe, and avoid metal lids that can corrode in contact with acidic brine unless they are coated. Plastic lids or lined lids are usually a better match for long storage. If you notice rust or a metallic smell, move the sauerkraut to a different container.

A last practical point is portioning. If you eat sauerkraut slowly, scoop a week's worth into a small jar and keep the main batch sealed and cold. Every time a jar is opened, it meets new air and new microbes, so fewer openings generally means a longer, more predictable life for the rest of the batch.