RED CABBAGE SAUERKRAUT
We planted a row of red cabbages last Spring for the specific purpose of making red sauerkraut in the Fall. 
We had heard that red cabbage is very sensitive to iron contamination, which will cause it to turn a dirty pink color. It will still be edible, just not very attractive. This makes sense, because in working with natural dyes, adding an iron salt as a mordant is called "saddening", as it tones down the resulting color. We were very careful to use only plastic and glass containers, stainless steel cutting implements, and rinsed everything repeatedly in distilled water, fearing that there might be too much iron in our well water.
We picked ten red cabbages and went to work, removing the outer layers and quartering them in preparation for slicing. One of the stranger discoveries of this year is that one of the cabbages had a nest of tiny brown ants living between the layers of leaves! We quickly threw that one outside, spilling as few ants as possible.
The Farm Journal's Freezing and Canning Cook-Book had a recipe for making sauerkraut in a glass jar. Whenever we got 5 pounds of shredded cabbage, we'd mix it well with 3-and-a-half tablespoons of kosher pickling salt and put it into the 5-gallon glass jar shown in the picture. The salt and cabbage had time to react while we were slicing the next 5 pounds. Before putting the next batch into the jar, we'd press down the last batch very firmly until it was covered in its own juice.
The nine cabbages weighed about 19 pounds and filled the 5-gallon jar to within three inches of the top. We put a damp cloth inside the jar to cover the top of the kraut; there was enough juice to cover the cloth, even after absorption. To seal it, we put about two quarts of water into a double plastic bag and tied the bags with a twist tie. This was placed inside the neck of the jar, resting directly on the covering cloth. The advantage to this is that the bag settles down to fill the space at the top of the jar, making a seal to keep bugs out and evaporation to a minimum, while adding the weight needed to keep the kraut compressed during fermentation. It is not so heavy or tight a seal that it prevents the fermentation gasses from seeping past, however. In the two weeks of fermentation, we only had to add a half-cup of brine to compensate for fermentation and keep the kraut moist.
We were relieved to see, day after day, that fermentation wasn't affecting the nice fuchsia color of our kraut. We canned it in one-pint jars after two weeks, using the usual method of heat sealing the jars by boiling them for a half hour in an open canning bath. Again, we were relieved to find that the color was not affected by heat. Our fears about the iron contamination seem to have been confirmed, however. In trying to get the last bit of kraut out of the aging jar and into the canning jars sitting in the hot water bath, some was dropped into the hot water. This was an old porcelain pot with a few chips where the iron core showed through. The bits of kraut that had been cooked in the bath water turned a dark blue, while the kraut in the canning jars kept its color.
The red cabbage sauerkraut has the same texture and taste as regular kraut and adds a splash of color to our meals, but we haven't yet had the nerve to try it in a Reuben sandwich.
