I've been fermenting sauerkraut in a quart jar and for some reason forgot to keep an outer piece of cabbage to help keep the kraut submerged. For day 1-2 it was fine, there was plenty of brine to keep it submerged. Now though on day 3 and 4 the brine has all been reabsorbed into the kraut and no matter how much I push it down, in a few hours it's exposed again. Do I still need to worry about mold at this stage or has 2 or 3 days fermentation been enough to preserve it? Or should I top off with a brine solution or would this just add unnecessary salt to what should be now a pickled flavour?