How Long Sauerkraut Lasts in the Refrigerator

Unopened sauerkraut lasts one to two years in the refrigerator

An unopened jar of sauerkraut will stay safe to eat for one to two years when stored in the refrigerator, even though the expiration date on the label may say something different. The acidity and salt content in sauerkraut act as natural preservatives, which is why it lasts so much longer than fresh cabbage. The cold temperature of your refrigerator slows any remaining fermentation and keeps harmful bacteria from growing.

The key is that the jar stays sealed. Once you open it, the timeline changes significantly. The fermentation process that preserved the sauerkraut in the first place continues slowly in the cold, and exposure to air introduces new variables. Most opened jars will stay good for three to six months if you keep the lid on between uses and store it in the coldest part of your refrigerator—usually the back of a shelf, not the door.

If you notice the sauerkraut has developed a white film on top after opening, that is kahm yeast, which is harmless but affects flavor. You can skim it off. If you see pink or orange discoloration, mold, or smell anything off-putting, throw the jar out.

Key Takeaways

• Unopened sauerkraut lasts one to two years in the refrigerator because salt and acid preserve it naturally.
• Once opened, sauerkraut stays fresh for three to six months if you keep the lid sealed and store it in the coldest part of your refrigerator.
• White film on the surface is harmless kahm yeast and can be skimmed away, but pink discoloration or mold means you should discard the jar.
• Store sauerkraut in the back of a shelf rather than the door, where temperature fluctuates and it will spoil faster.

Why the door is the worst place for sauerkraut

The refrigerator door is the warmest part of your fridge because it opens and closes constantly, letting warm air in each time. Sauerkraut is sensitive to temperature swings. When the temperature rises and falls repeatedly, the fermentation can restart and speed up, which shortens how long the jar stays good. The salt and acid that preserved it for months can become overwhelmed by new bacterial activity.

Store opened sauerkraut on a middle or back shelf instead, where the temperature stays steady. If your refrigerator has a dedicated cold storage zone or a drawer designed for vegetables, that works too—just make sure the jar is sealed tightly. The steadier the temperature, the longer your sauerkraut will last.

Signs sauerkraut has gone bad

Sauerkraut is one of the safer fermented foods because the fermentation process itself creates an environment where harmful bacteria struggle to survive. That said, you should still know what to look for. Mold is the clearest sign to throw it out—it will appear as fuzzy growth, usually white, green, or black. Pink or orange discoloration is also a red flag and means harmful bacteria have taken hold.

Smell is another reliable indicator. Fresh sauerkraut has a sharp, tangy, vinegary smell. If it smells rotten, musty, or like something has died, do not eat it. A sour smell that is stronger than usual but not actively unpleasant is normal as sauerkraut ages, but if you are unsure, trust your nose.

Texture changes are less reliable as a warning sign because sauerkraut naturally softens over time in the refrigerator. However, if the cabbage becomes slimy or falls apart when you try to pick it up, that is a sign fermentation has gone too far and you should discard it.

How to store opened sauerkraut so it lasts longer

The moment you open a jar, bacteria from the air and your utensils can enter. To slow spoilage, always use a clean fork or spoon to remove sauerkraut—never your fingers. Wipe the rim of the jar with a clean paper towel before closing the lid, because dried sauerkraut or brine on the threads can harbor bacteria.

Keep the lid on tight. If the original lid no longer seals well, transfer the sauerkraut to a smaller jar with a tight-fitting lid so there is less air space above the brine. The brine itself is protective, so make sure the cabbage stays submerged. If the level drops below the top of the sauerkraut, add a little salt water (one teaspoon of salt per cup of water) to keep it covered.

Store the jar in the coldest part of your refrigerator, ideally between 32 and 40 degrees Fahrenheit. If your fridge runs warmer than that, sauerkraut will not last as long. Check the temperature with a refrigerator thermometer if you are unsure.

Homemade sauerkraut lasts longer than store-bought in some cases

Homemade sauerkraut that you ferment yourself and then refrigerate can last longer than commercial sauerkraut because you control the salt content and fermentation time. If you ferment it fully and use enough salt, the acidity will be high enough to preserve it for years. However, homemade sauerkraut that is not fermented long enough or does not have enough salt will spoil faster than store-bought versions.

Store-bought sauerkraut is often pasteurized, which kills the live cultures but also makes it more stable and less likely to continue fermenting in your fridge. This is why commercial sauerkraut often lasts the full one to two years even if the jar sits in the back of your fridge unopened. Unpasteurized, raw sauerkraut from the refrigerated section of the grocery store will ferment more actively and may not last quite as long, though it still typically keeps for months.

What happens if sauerkraut freezes in your refrigerator

If your refrigerator is set too cold and sauerkraut freezes, the texture will change when it thaws. The cabbage becomes mushy and loses its crunch. The flavor usually stays intact, so it is still safe to eat, but it will not have the same appeal as a crisp bite of sauerkraut. If you want to use frozen sauerkraut, cook it into a dish rather than eating it straight from the jar—it works well in soups, stews, or braised meats.

To avoid freezing, keep your refrigerator at 40 degrees Fahrenheit or slightly above. If you have a freezer compartment in your fridge that is very cold, do not store sauerkraut there unless you plan to use it in cooked dishes.

Sauerkraut in the refrigerator versus the pantry

Unopened sauerkraut can technically sit in a cool, dark pantry for several months, but the refrigerator is the better choice. Room temperature speeds up fermentation and can cause the jar to bulge or even burst if pressure builds up inside. The cold of the refrigerator slows fermentation to a crawl, which is why unopened jars last one to two years instead of a few months.

Once opened, sauerkraut must go in the refrigerator. There is no safe way to store opened sauerkraut at room temperature. The combination of exposure to air and warm temperature creates ideal conditions for harmful bacteria to grow.

Frequently Asked Questions

Can I eat sauerkraut after the expiration date if it has been unopened?

Yes, unopened sauerkraut is usually safe to eat for one to two years past the printed date because the salt and acid preserve it. Check the jar for bulging, leaks, or rust before opening. If the jar looks normal and smells right when you open it, it is fine to eat.

Why does my opened sauerkraut smell stronger than it did in the jar?

Sauerkraut continues to ferment slowly in the refrigerator, and fermentation produces more acid and sulfur compounds, which intensify the smell. A stronger smell does not mean it has gone bad—it just means the fermentation is still active. If the smell is rotten or musty rather than sharp and tangy, discard it.

Is it safe to eat sauerkraut with white film on top?

Yes, white film is kahm yeast, which is harmless. Skim it off with a clean spoon and discard it. The sauerkraut underneath is still safe. Pink, green, or black mold is different and means you should throw the whole jar out.

How do I know if my refrigerator is cold enough for sauerkraut?

Your refrigerator should be between 32 and 40 degrees Fahrenheit. Buy a refrigerator thermometer at any grocery store and place it on a shelf for a few hours to check. If it reads above 40 degrees, sauerkraut will not last as long.

Can I store sauerkraut in a plastic container instead of glass?

Glass is better because it does not absorb odors or flavors and does not react with the salt and acid in sauerkraut. Plastic containers can absorb the smell and may degrade over time. If you must use plastic, choose a food-grade container and replace it if it becomes cloudy or brittle.