This ferment is just over 30 days noticing there are still bubbles curious if it could be O2 after reading about how to make kraut it says there shouldn't be any bubbles to keep pushing it down when you see them . Pics upside down come on lol
It's almost certainly just C02 from the fermentation. What you can do is, keeping the jar flat and level, but in the air not on a surface, twist it around partway from side to side so the jar twists separately from the contents. This will cause the bubbles escape and rise to the surface, which can help reduce the contents tendency to rise from the bubbles. Also, when you see bubbles form again the next day, you'll know it's still fermenting. And when the bubbles stop...