I am no expert, but I think the sauerkraut has to be naturally fermented the old fashioned way, not canned or made “fake sauer” by using vinegar.
Same goes for anything else “fermented”, has to be the old- fashioned way, in a crock, on the counter, with only salt and water.
The canning process would kill the organisms that do the work. So, no process manuyfactured stuff. Make your own yogurt!
“Make your own yogurt!”
I could do that — for my husband. Just the smell of yogurt makes me gag. Could not possibly eat it.
Will look for the real deal sauerkraut, which I love.