My go-to for these questions is stilltasty.com. Was it a refrigerated product? If not, 5-7 days. If so, read at the site, I think they’re saying six months but I’m not clear on if that really means opened.

Thanks so much! I bookmarked the site. Looks like my best bet is to divvy it up and freeze it. Thanks again! Happy New Year!

It seems like the same question as asking how long a pickle will last. It's just pickled cabbage instead of pickled cukes. I'd use it unless it grew mold, which it probably won't do for months and months.

There must be a reason that they give the shelf stable canned product an extremely shorter window though.

Found my answer. Excerpts from link below.

The other variety is sold unrefrigerated, and it usually is the same fermented cabbage, just pasteurized afterward. It’s shelf stable, as most if not all of the bacteria were killed during the pasteurization, so it’s no longer fermenting.

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When it comes to the shelf-stable fermented cabbage, it stays fine in the fridge for up to a week after opening. There’s nothing there that will keep it alive for longer.

https://www.doesitgobad.com/does-sauerkraut-go-bad/

Shelf stable, from the non-refrigerated shelf of your market, will be edible a bit longer than the 5-7 days but cabbage has an enzyme not found in a cucumber. Looses its texture and deteriorates faster. I've never looked at a label since I have natural ferments going at all times but they might have other ingredients to keep it longer once opened and in your fridge.

And shelf stable is 'pasteurized', heat treated to about 180, so no beneficial bacteria exists. Beneficials are killed off at 106. So if you want the benefits, buy it from the refrigerated section and look for an 'un-pasturized' brand. That will keep much longer, up to six months or so but all natural ferments will loose some freshness and crunch. Refrigeration 'slows' the fermentation process. Some like it with a older fermented tang.

Those of us that ferment have a moment when we refrigerate, say 10 days, to hold it longer, slow it down, using cold fridge temps.

I do small batch, 2-4 quarts at a time...kimchi and krauts.

Excellent information and recipes, linky HERE

Yeah, I really should have bought one of the small cans instead of the larger jar but I really don't care for the "tin can after-taste" I always detect. Thank you all very much, New Year is only a day old and I've learned something already!

Sleevendog, people, for generations have keep cabbage fermenting for months in a root cellar, so I don't think it's shelf life is any different than a cuke would be when fermented and kept cold.

It was unclear that the op was talking about canned, pasteurized sauerkraut. Around here, and I imagine other places, there are many companies selling refrigerated, jarred, live fermentation sauerkraut and pickles, kimchee, etc. When the op said opened a jar, I assumed that was what she meant.

Glad that was clarified, so there is no error, but I imagine "spoiled" shelf stable sauerkraut would be easy to spot/smell. Nothing quite like rotten cabbage! Well, maybe rotten cooked broccoli, lol!

I sporadically make Ruebens for DH and me. I keep the sauerkraut in the freezer flattened in a ziplock bag. That way, I can break off what I need without thawing the whole thing.

Yes, I'm aware of the histories of fermentation. Our op read the link foas posted. Why she decided to freeze it as recommended by the site.

I was just pointing out shelf stable does not have the good gut benefits. Some might be eating kraut for that reason and should get the correct brand.

I have a root cellar and crocks but prefer the small batch method. Easier for just the two of us and can rotate out different vegetables. I don't grow big cabbage crops so I have no need to preserve for the winter like past generations.

Cabbage kraut and kimchi gets funky, cucumber pickles not so much. Black radish will clear a room. Smells like a restaurant dumpster on a hot day. All perfectly edible if you can get past the smell.

It is sodium benzoate that is used in some shelf stable. Might be what will keep it longer than the 7days in the fridge....but freezing like mentioned would be best for preserving the flavor.

Yes, I only got the kraut mostly as a condiment to go along with some bratwurst, so I wasn't thinking about anything but the flavor. It was the kind you get in a jar from the canned veg aisle. We didn't use much of it so I am freezing it in small packets to have in a few months when we do brats on the grill. It doesn't take much since DH isn't really a fan either.