My cabbage has been fermenting a week. About every two days I check it and skim off the "scum" that forms on top, but today there were just a few bubbles. That tells me that the fermentation is slowing down and entering a different stage. The sugars in the cabbage are being broken down into lactic acid, which is a potent digestive aid. The kraut no longer smells like "stinky old man farts" but now smells sweet and tangy.
I gave it a good stir today just so I could check it out. The cabbage is still crisp. I even tasted it (and lived to tell about it!) It's sweet and tangy and just a little salty, definitely on it's way to kraut I can tell.
I'll give this bad boy another week to brew and we'll see how it turns out. I've still got about four heads of cabbage that need to be processed some how. I'd like to make another batch of kraut, but if this doesn't turn out we may be eating cole slaw and stuffed cabbage leaves for the next month!