Sauerkraut, a fermented cabbage dish, is often touted for its long shelf life. But even this relatively stable fermented food can eventually go bad if not stored properly. So how long does sauerkraut last in the fridge, and what are the signs that it has spoiled?
Quick answer
Properly fermented and stored sauerkraut can last for months or even years in the refrigerator. Look for signs of mold, yeast growth, unpleasant odors, or slime to determine if sauerkraut has spoiled.
How long does sauerkraut last in the fridge?
An unopened jar of refrigerated sauerkraut will typically stay good for 6 to 12 months past the “best by” date on the packaging. Once opened, sauerkraut will last for about 2 to 4 weeks in the refrigerator.
The exact shelf life depends on a few factors:
- Freshness when purchased – Fresher sauerkraut will last longer.
- Storage container – An airtight container helps block oxygen and slows spoilage.
- Temperature – Colder refrigerator temperatures (34-35°F) extend shelf life.
- Fermentation – Fully fermented sauerkraut lasts longer.
- Preservatives – Some store-bought sauerkraut contains preservatives for a longer shelf life.
Properly fermented and stored sauerkraut packed with naturally occurring lactic acid bacteria can potentially stay edible for several years in the refrigerator. Over time, it may slowly lose some texture, tanginess, and vitamin content, but remains safe to eat.
How to tell if sauerkraut has gone bad
Sauerkraut can spoil or become unsafe to eat if stored incorrectly or for too long. Here are signs that refrigerated sauerkraut has gone bad:
Appearance
- Mold – Fuzzy mold growing on the surface or brine indicates spoilage.
- Sliminess – A slippery, slimy texture or sheen on the brine.
- Dryness – Shriveled or dried cabbage leaves.
- Pink or white film – Growth of yeast like Kahm yeast can form a film or bloom.
- Soft texture – Sauerkraut should have a crisp crunch. Soft or mushy leaves are a red flag.
Smell
- Rotten or putrid odor – Foul, sulfurous smells signal spoilage.
- Vinegar-like smell – Sharp, unpleasantly acidic smell.
- Alcoholic odor – Fruity or yeasty smell from fermentation going awry.
- Ammonia smell – Pungent ammonia-like smell indicates protein breakdown.
Taste
- Bitter flavor – Bitterness or rancidity.
- Slimy texture – A slippery mouthfeel when eaten.
- Fizziness – Carbonation or fermentation fizz can mean spoilage.
How to extend shelf life of sauerkraut
To maximize how long sauerkraut stays fresh in the refrigerator, keep these tips in mind:
- Purchase freshly made sauerkraut whenever possible.
- Check “best by” dates and choose packages farthest from expiration.
- Inspect jars for signs of spoilage before purchase, like bulging lids or slimy brine.
- Store unopened jars in a cool, dark pantry away from light and heat.
- Refrigerate opened jars at 34-35°F. Colder temps prolong shelf life.
- Keep sauerkraut submerged in brine to prevent oxidation.
- Use clean utensils when removing sauerkraut to avoid introducing bacteria.
- Never return used sauerkraut to the original jar.
- Store in tightly sealed glass or plastic containers rather than metal cans.
- Freeze for longer storage. Sauerkraut keeps 6-8 months frozen.
What happens if you eat spoiled sauerkraut?
Moldy, rotten, or improperly fermented sauerkraut can contain harmful bacteria that may cause foodborne illness if consumed. Symptoms include:
- Nausea or vomiting
- Diarrhea
- Abdominal pain or cramping
- Fever
- Headache
- Fatigue
In severe cases, food poisoning from sauerkraut can even cause confusion, muscle aches, and signs of infection. Seek medical care if symptoms are serious or persist more than a day or two.
Some molds that grow on spoiled sauerkraut may also produce mycotoxins that can pose health risks when ingested. It’s best to err on the side of caution and discard sauerkraut that shows any signs of spoilage.
Can you rescue spoiled sauerkraut?
It’s usually not recommended to try to rescue a batch of sauerkraut that has begun to spoil. The microbes responsible for the proper fermentation can be thrown off balance, making it difficult to recover the sauerkraut even if signs of spoilage are removed.
Here are potential ways to try to rescue spoiled sauerkraut, though success is not guaranteed:
- Skim mold off surface – If a small patch of surface mold has formed, it may be possible to skim it off along with 2 inches of sauerkraut below. Thoroughly clean the container with boiling water before replacing the sauerkraut.
- Re-pack sauerkraut – Transferring the sauerkraut to a clean container may help if the original container introduced contaminants.
- Add starter culture – Stirring in whey from fermented foods or an active culture starter may revive fermentation.
- Re-ferment – Attempting a renewed ferment for 1-2 weeks may salvage the sauerkraut, but success depends on the type of spoilage present.
However, sauerkraut that has developed a strong unpleasant odor, scary mold growth, or slimy texture is typically too far gone and best discarded.
Can you freeze sauerkraut?
Freezing is an excellent way to extend the shelf life of sauerkraut beyond typical refrigerator storage. Properly frozen sauerkraut remains safe to eat for up to 8 months.
To freeze sauerkraut:
- Make sure sauerkraut is fully fermented before freezing for optimal texture and tang.
- Allow to chill completely in the refrigerator before freezing.
- Portion into reusable freezer-safe containers, leaving 1⁄2 inch headspace.
- Remove as much air as possible and seal lids tightly.
- Label containers with contents and freeze-by date.
- Freeze at 0°F or colder.
Some key tips for freezing sauerkraut:
- Glass jars or plastic freezer containers are good choices.
- Avoid metal cans or foil which can cause off-flavors.
- For softer texture, freeze in brine. Or drain well and freeze on a sheet pan before packaging.
- Thaw overnight in the refrigerator before use.
- Use thawed sauerkraut within 5 days.
While freezing stops microbial growth that causes food spoilage, it does not kill all bacteria already present. Always practice food safety when handling and thawing frozen sauerkraut.
How to store sauerkraut long-term
In addition to freezing, sauerkraut can also be canned or pickled for long-term room temperature storage of up to 12 months or more.
Canning sauerkraut
Properly canned sauerkraut keeps for 12 months sealed in sterilized canning jars. Key tips for canning success:
- Use fully fermented sauerkraut.
- Adjust recipes as needed for your altitude.
- Carefully follow canning directions.
- Use a water bath canner, not pressure canner.
- Store sealed jars in a cool, dark place.
- Discard any jars with broken seals or signs of spoilage.
Pickling sauerkraut
Sauerkraut can also be pickled in vinegar for longer unrefrigerated storage. Refrigerate after opening.
- Drain and rinse fermented sauerkraut.
- Pack sauerkraut and spices into sterilized jars.
- Pour hot vinegar brine over sauerkraut to cover.
- Adjust vinegar pH for safe room temperature storage.
- Process pickled sauerkraut in a water bath canner.
- Store sealed jars at room temperature out of sunlight.
Both canning and pickling require following tested recipes precisely to prevent the risk of botulism or other foodborne illness.
Sauerkraut shelf life chart
Here is a quick overview of expected sauerkraut shelf life under various storage conditions:
| Storage Method | Shelf Life |
|---|---|
| Refrigerator (unopened) | 6-12 months past “best by” date |
| Refrigerator (opened) | 2-4 weeks |
| Freezer | 6-8 months |
| Canning (unopened) | 12 months |
| Canning (opened) | 1-2 weeks |
| Pickling | 12 months (unopened) 1-2 weeks (opened) |
Remember to watch for signs of spoilage no matter how sauerkraut is stored. Discard any questionable sauerkraut instead of risking foodborne illness.
FAQ
Why does sauerkraut go bad?
Sauerkraut can spoil when harmful bacteria or molds grow out of control or yeasts change the fermentation balance. Lactic acid bacteria help preserve sauerkraut, but environmental factors like oxygen, moisture, or temperature changes allow undesirable microbes to take over.
Can you eat sauerkraut that is slimy?
No, slimy sauerkraut should be discarded. Sliminess is often caused by spoilage microorganisms like yeasts or harmful bacteria. Consuming slimy sauerkraut puts you at risk of food poisoning.
Does sauerkraut need to be refrigerated after opening?
Yes, always refrigerate sauerkraut after opening. The anaerobic environment needed for long term storage no longer exists once exposed to air. Refrigeration helps slow further microbial growth and enzymatic reactions.
How do you know if opened sauerkraut is still good?
Look for signs like crisp texture, bright color, tangy aroma, and lack of slime, foam, or mold. Refrigerated sauerkraut can last 2-4 weeks after opening if stored properly. If any signs of spoilage appear, play it safe and discard.
Can expired sauerkraut make you sick?
Consuming spoiled, moldy, or expired sauerkraut can potentially lead to foodborne illness. Even if it doesn’t look or smell bad, sauerkraut well past its prime lacks the beneficial probiotics and can harbor harmful bacteria.
Conclusion
With proper refrigeration and food safety practices, an opened jar of sauerkraut can continue providing tangy flavor for weeks after opening. For storage beyond 4 weeks, freezing or canning helps prolong shelf life further. While sauerkraut’s high acidity and lactic acid bacteria act as preservatives, it isn’t foolproof against spoilage. Keep an eye out for any change in appearance, texture, or smell that could indicate it’s time to discard your leftover sauerkraut. When in doubt, remember it’s better to be safe and start fresh with a new jar.
