Failsafe Fermentation

Fresh out of college, I took a teaching job in Racine, Wisconsin, just downwind of the small Wisconsin town of Franksville. The town was surrounded by fields of cabbage, and every fall that cabbage was turned into kraut – Franks Kraut – and the air
downwind of the town smelled of fermenting cabbage. The large number of German immigrants and the ready availability of German cuisine in the area made sauerkraut a common part of meals, and when we moved to Iowa and later, Washington, we carried our taste for kraut with us.

The problem with the kraut we had been eating, however, was that it had been canned, a process that killed all the fermenting bacteria, so the probiotic benefits of the kraut had been lost. We bought freshly made deli kraut from the grocery refrigerator section but found it too sour – and too expensive. It was time to learn to make our own kraut.

Recipes for making kraut are easy to find. According to the recipes, all one needs to do is:

• Shred a three-pound head of cabbage,
• Combine the shredded cabbage with 1 1/2 tablespoons of salt,
• Knead the salted cabbage until a good amount of juice is released,
• Put the resulting juicy shredded cabbage in a clean mason jar,
• Tuck a leaf of cabbage inside the neck of the jar to keep the shreds from floating out during the fermentation
  process, 
• Cover the jar with a cloth to keep out troublesome insects, mold, and bacteria, and set it in a dark, cool place.
• In a week the kraut will be ready to use or to store into refrigerator. 
• If you like your kraut less sour, start eating/storing it earlier, and if you like it sourer, extend the fermentation time.

We followed the recipe, and our first attempt was a success, except for the fact the fermenting juice started rising out of the jar, but we managed to catch the juice in a platter, and the resulting kraut
tasted just right. The next jar spoiled while fermenting: the cabbage leaf had been lifted by the fermentation bubbles, so the kraut developed a mold and rotted. The same thing happened to the third jar. 

There HAD to be a better way to make kraut. Two
simple devices solved the problems. One was using a glass weight to hold the top cabbage leaf down, and the second was an air lock.

Air locks let the fermentation bubbles out, but allow no air or contaminants to come in. Air locks for mason jars come in at
least two varieties. One is a flat silicon disk whose protruding nipple includes a tiny hole that lets gas escape: