Kraut is for long term storage...keeps nearly for ever....well at least for several months.
I bet the sauteed onions will compromise the keeping qualities though....because kraut depends on lactose fermentation to "keep" and the onions have not been fermented and introduce some fats.
I buy the refrigerated kraut, comes in a plastic envelop. Contains the live ferment and leftovers keep in my refrig until they are gone...months!

I left a CAN in the refer once and it seemed to go bad in a week or so. However, I therefore buy the bigger size in a JAR, with a lid of course. It keeps for months. My major need is an addition to a couple hot dogs so I use little at a time. I can consume more if I'm into some sausages with potato or something similar.

I suspect that the acid would protect onions if they were well mixed, but I have no experience and don't intend to get any.

I agree with chas, properly fermented sauerkraut can keep for months in the refrigerator. I make my own and it sits in a crock until it's "right", and then I can it. It can be frozen and many people do that, but it takes up my precious freezer space, so that doesn't happen here. Grandpa's sauerkraut crock sat the in the root cellar all winter, and we just went and dipped some out when we wanted it. It just got more and more "sour".

However, most commercially prepared sauerkraut isn't actually fermented, that takes too long. Check the jar, is there vinegar? Brands like Vlasic are more pickled than truly fermented, and so that MIGHT help the onion, but I wouldn't be completely convinced as I have no way to determine the ratio of vinegar to product.

Annie

I freeze leftover sauerkraut in small containers, and it's fine for cooking. But more often than not, I forget it's in the freezer and it gets lost, like socks in a dryer.

You can make sauerkraut cake: http://www.geniuskitchen.com/recipe/sauerkraut-cake-255376

You can freeze it as mentioned. I ferment so made a quick 3 day kraut for the weekend, then packed the leftovers with more cabbage in layers and now fermenting. Our grocery was given away cabbage with minor purchase so we have extras I'll make some kimchi next weekend....

I remember sauerkraut salad always appeared at our family get-togethers. I do not have the recipe but did find one that sounds like it (I don't remember apple in it but that sounds very good!)

https://anaffairfromtheheart.com/2016/04/sauerkraut-salad/

I guess I accidentally purchased a very good sauerkraut. Deutsche Kuche German Style Sauerkraut. Ingredients: Cabbage, Salt. Glass jar, metal top. Purchased at Aldi (Of course, a German based company).

Gary, you did pick a good brand, it's clearly fermented instead of pickled. Open and intact, it should keep for a long time. Add the onions and I think it's compromised, as the onions are not fermented with the cabbage.

Annie

drain the juice. add some sugar ( 1/2 CUP) and set in fridge at least 48 hours.

can add peppers, diced celery and grated carrot. add a smidge of oil.

nice sweet sour salad … hit at potlucks for those brave enough to try.

great on pizza too.

Gary, I've read that if you will just dip in and eat a forkful every day you will notice a big difference in your health.

Dandy, I think you are reading about naturally fermented kraut and not processed cans and jars.

It has something to do with feeding the Microbiome the culture of which lives in, around, and throughout your body and controls a lot more of you than you are probably willing to admit. The comments are that sauerkraut, among other fermented items are beneficial to your Microbiota. Now you have me wondering, do they mean canned, jarred, or other sauerkraut.

Sauerkraut that is "natural" that has no vinegar added....the sour comes from lactobacilli. Check the label...I find the best in the refrigerator section in a plastic pouch.

The probiotics and good stuff in sauerkraut are compromised by heat. I can mine because I'm going to heat it to eat it anyway, so it's kind of a moot point for me. The healthiest, though, is the fermented stuff, refrigerated and not canned, and eaten without heating. If you want to do that. Freezing apparently helps preserve those good probiotics which are killed by heat.

Annie

I eat it right out out of the, store bought, jar. It lasts for months in the fridge. I love sauerkraut!

Please, more suggestions on how to use sauerkraut?

I tried a recipe last year using sauerkraut and liked it so well that I bought a couple more jars when I saw it on sale.... but have since forgotten what the recipe was and where I saw it! I am sure it was not a cake, though! Maybe a soup or casserole?

I can't see myself using up these jars otherwise. I don't eat hot dogs, rarely eat kielbasa. I'll try the salad that bragu mentioned -- if it is good on pizza that will be a winner!

Pan fry pork chops to a good sear on them. Sautee a chopped large onion, Add 8 oz sauerkraut and 8oz water. Let it steam for an hour. Fall-of the bone goodness.

I added it to a cake mix to imitate carrot cake. Sauerkraut Brownies? YES!

Chopped up and mixed with Mashed Potatoes: almost a colcannon.

I hope more recipes happen here.....

Was rushing to post the pork chop thing....but you can made a 'casserole' of lean pork, like a shoulder steak, potatoes, a sliced onion and kraut...start with a layer of kraut in a dish with a good lid ( or you can cover with foil) add a pork steak...big enough to cover the kraut, add a sliced onion and a sliced potato and salt and pepper well....cover and cook on lot for about 1 1/2 hours.

Raee … what do you mean IF it's good on pizza. You never had a german pizza? Canadian bacon, pineapple and sauerkraut. It's a flavor you'll learn to appreciate … or not.

bragu, no I have not! I like muffaletta on pizza, perhaps I would like sauerkraut -- I will try it.