Sauerkraut is one of the longest-keeping foods in your fridge: raw, refrigerated kraut stays good for four to six months and frequently far longer, because the same salt and lactic acid that ferment cabbage also preserve it. Store-bought refrigerated jars keep for months once opened, shelf-stable canned kraut lasts one to two years in the pantry, and you can freeze it for up to a year — though freezing and heat both knock down the live probiotics.
How long does sauerkraut last in the fridge?
Refrigeration is where sauerkraut shines. Cold (below 4°C / 40°F) slows fermentation almost to a standstill, so a finished kraut just keeps getting slowly more sour without spoiling. The exact window depends on how it was made and whether it’s been opened:
Homemade raw sauerkraut has no fixed expiry — as long as it stays cold, stays under its brine, and tastes and smells clean, it’s good. Many home fermenters keep a crock going for a year or more; the flavour just softens and deepens. Store-bought refrigerated kraut carries a best-by date, but that’s a quality guideline, not a safety cliff. Opened jars typically stay excellent for several months in the fridge.
Homemade vs store-bought: what's the difference?
Not all sauerkraut is preserved the same way, and that changes how long it lasts and what benefits it carries.
The quick tell: if you bought it cold, keep it cold and treat it as a live food. If you bought it off a warm shelf, it’s pasteurised and pantry-stable until you open it — then it moves to the fridge.
Pantry & canned sauerkraut
Shelf-stable sauerkraut — the canned or jarred kind sold at room temperature — has been heat-treated to kill off all microbial activity, including the probiotics. That trade-off buys shelf life: unopened, it keeps for one to two years in a cool, dark cupboard and stays safe well beyond the printed date as long as the can or lid seal is intact and undamaged.
Once you open it, the rules change completely. It’s no longer sterile, so transfer it to the fridge in a covered container and use it within a few weeks to a couple of months. Never store an opened can of kraut in the can itself — decant it into glass or plastic.
Can you freeze sauerkraut?
Yes — sauerkraut freezes well for long-term storage and lasts up to a year in the freezer. The catch is that freezing comes at a cost to the two things people love kraut for: texture and probiotics. Ice crystals rupture the cabbage’s cell walls, so thawed kraut is noticeably softer and less crisp, and the cold damages and reduces the live lactic-acid bacteria.
- 1Portion it Divide the kraut into meal-sized amounts so you only thaw what you need. Refreezing repeatedly degrades texture further.
- 2Keep some brine Pack each portion with enough of its own brine to cover, or at least coat, the kraut — the brine protects flavour and helps preserve what live cultures survive.
- 3Leave headspace Use airtight bags or rigid containers and leave room at the top; the liquid expands as it freezes and will crack a full container.
- 4Label & date Mark the bag with the date and aim to use it within 8–12 months for the best quality.
- 5Thaw in the fridge Move it to the fridge overnight rather than thawing at room temperature. Drain off excess liquid before serving.
If gut-health benefits are your priority, keep your everyday kraut in the fridge and reserve the freezer for gluts or long-term stashing.
Freezing and heat both reduce the probiotics
The living part of raw sauerkraut is fragile in a way the food itself isn’t. The kraut can stay safe to eat for a year while its probiotic value quietly drops.
The practical takeaway: to get the probiotic benefit, eat raw refrigerated kraut, and if you’re adding it to a hot dish, stir it in at the very end off the heat rather than simmering it.
Free Fermentation Salt Reference Card (printable PDF)
A printable PDF companion for the brine & pickling calculators and guides.
Keep it under the brine
The single biggest factor in how long your kraut lasts is whether it stays submerged. The brine is an acidic, salty, low-oxygen zone where spoilage moulds and film yeasts can’t take hold — but the good lactic-acid bacteria thrive. Anything poking above the surface is exposed to air and becomes a foothold for mould.
After every time you dig in, press the kraut back down with a clean fork so the brine covers it again. If the level has dropped, top it up with a little extra brine made from the right salt ratio — roughly a 2% salt solution — rather than plain water, which would dilute the acidity. Always use a clean utensil; a dirty spoon is the fastest way to introduce the mould or off-bacteria that shorten a jar’s life.
Normal signs — not spoilage
Plenty of things that look or smell alarming to newcomers are completely normal for a live ferment. Before you toss a jar, check these off:
Signs sauerkraut has gone bad
Genuine spoilage is uncommon in properly made kraut, but it does happen — usually to the part that sat above the brine or to a jar contaminated by a dirty utensil. Throw it out if you see any of these:
Watch for
- Fuzzy mould of any colour — white-and-fuzzy, green, black, pink, or blue — on the surface
- A rotten, putrid, cheesy, or otherwise foul smell (a clean sour smell is fine; a rotten one is not)
- A slimy, snotty, or ropey texture, or brine that has turned thick and stringy
- Pink or discoloured streaks through the kraut (often a sign the salt level was too high)
- A bulging, hissing, or leaking lid on a shelf-stable can — do not taste it, discard it
Note the difference between mould and kahm yeast: a thin, flat, white, wrinkly film on the brine surface is kahm yeast — harmless if skimmed off promptly, though it can taint the flavour. Anything fuzzy, raised, or coloured is mould, and mould means the batch goes in the bin. When a smell or texture is genuinely off, don’t taste to check — trust your nose and eyes and discard.
