Last year I tried making sauerkraut for the first time using mason jars. It was fantastic, but basically consisted of massaging the cabbage with salt until a brine started forming, and then compressing it in the mason jar under a weight (a smaller mason jar filled with water) so it stayed submerged.
For Christmas, my wife bought me a 5L German Style Harvest Pot (made by TSM Products). I made a half batch of kraut using essentially the same technique, poured some extra brine solution on top to make sure it started off submerged, and weighted it down with the stone weights. I placed the cover on and sealed with water. After a couple days, I noticed the water seal was gone - it may have dripped into the pot, but I think it might also have evaporated (as there was some salt residue). I transferred the pot to a cool basement, made another brine solution and sealed it again. Now I checked it two weeks later, and again the water seal was gone. I checked the kraut in the pot and the cabbage is fully submerged (under about an inch of brine. It certainly smells like kraut (ie, like an old German beerhall).
The first batch I had certainly didn't use a water seal, and that tasted great (and no one got sick). The technique with mason jars has the brine solution fully exposed to the air and seemed a pretty common way to make it. I don't really see a difference using a harvest pot like a big mason jar - but I get worried when talking about controlled bacterial processes.
My questions are these:
1. Is the water seal disappearing normal ? How can it be prevented ?
2. Does the fact the water seal disappeared mean I need to pitch this batch (I hope not, I was hoping to use it in a month for a party) ?
I've used water sealing before when making beer, but keeping the plastic cap full of water was not an issue.