Sauerkraut is bubbling and overflowing

[Jokester]

I started a sauerkraut with about 3/4lb of green cabbage ~2 days ago. This cabbage was left in brine overnight and it nicely let out a lot of water, I took some of the cabbage and ate it as a coleslaw salad that night and packed the rest into a glass jar and filled it up with the water. Basically I ate 1/4 a cabbage and put 3/4 of the cabbage with salt water and its own water.
Now to my taste it seems too salty, but its bubbling and in fact overflowing - which isn't a problem really, but does that mean its fermenting. And when its done overflowing, does that mean its done. Sadly I dont have an airlock on this jar, its a small glass jar with a plastic insert in the lid. I filled it with water/brine and the lid keeps any air from being in there, unless the co2 lifts it out and overflows.

 

[Tom R]

After the saltwater soaking, I always thoroughly rinse the salt off the cabbage before tamping it.

 

[Jokester]

Oh I ate that cabbage without rinsing it, it actually didn't taste salty. But you figure it didn't take in much salt in 12 hrs in the fridge, and all the salt was in the water and its now too salty. If bubbling = fermenting, I would be OK with the salt content, I seem to have a low tolerance for salt anyway. I find ketchup is too salty. Teriyaki glaze and BBQ sauces are unbearably so.

 

[Jokester]

Ok after 5 days it seems to not be bubbling as much, and the lid etc etc is fully plugged up with salt making it all airtight - I think. I'll let it run a month and taste from there and see.