I never tried with closed lids, I assume it can make it go off. I think the air needs to flow. If I don’t puncture my sauerkraut it goes off. I just noticed and so why I am doing it usually on Friday night so on weekends I am at home and can puncture it. I also leave a wooden stick permanently in, on a side of the jar so the gas will more easily.
Yes, you can keep it in the fridge and it will ferment, I read it some where but it will take two weeks. I am going to do my sauerkraut now.
I am going to try two litres, so it can last me longer.