Well, I came to this forum to post my sauerkraut recipe, but after reading this thread it seems everyone has a recipe. So, thought I would just post a few observations I've made over the years of making sauerkraut. Use what you like, ignore the rest.
1. Temperature is critical to the finished product and fermentation time required.
70-75 degrees -ideal temp -fully fermented in in 3-4 weeks
60-65 degrees -acceptable but may take up to 6 weeks
Below 60 degrees - probably will not ferment
Above 75 degrees - kraut will be soft and mushy and/or spoil
2. Only use a stone crock, glass or food grade plastic for fermenting (you can sterilize a plastic container by washing with bleach/water solution. Rinse throughly)
3. Weight on top of cabbage
a. Some people use a plate and jars of water or stone to keep cabbage submerged. However, this leaves the cabbage exposed to air and scum will form which must be removed daily.
b. I prefer to seal the top of crock by placing a plastic bag filled with a water/salt solution on top. With the surface sealed from open air the scum should not appear and you do not disturb the crock until fermentation is completed (stops bubbling).
4. Know the danger signs
Do not eat if you see mold on the surface, has a slimy texture or has a bad odor (not the normal kraut odor).
Ref: Penn State College of Agricultural Sciences
After all this, I must confess my last batch was a dismal failure...mush.
(temp was too high in heated room)