It's the traditional way to have vitamin C in abundance during the cold months in climatic zones like central Europe and large parts of the U.S or in Canada.
Sauerkraut was also used to prevent scurvy, because of it's keeping quality at sea and it's high vitamin C content.
In short, it's a fermentation of sugars contained in vegetables by a lactobazillus strain. The lactobazillus ferments the sugars into lactic acid. The acidity keeps unwanted bacteria and molds from taking over.
And as a "green" treat, you don't need external energy like in a freezer. Normal cellar temperatures are ok.
And of course the taste of a selfmade kraut beats every industrially fast produced product. It has even found it's way into the "haute cuisine". Have you ever tried a Champagnekraut with a nice fish? You will certainly be delighted.
Step 1: Ingredients
If you can't find exactly the same sort that we use, never mind and be creative. Try different sorts in small quantities to find out, which one you like the most.
What we use is a certain type of cabbage, typically grown on the "Fildern", which is southeast of Stuttgart.
It's called "Spitzkohl" or "Spitzkabis" pointed cabbage. They look like the Coneheads in the movie.
We were lucky to find them at a local organic farm.
For the most basic way to make Kraut, you only need two ingredients:
Cabbage and salt.
But traditionally, caraway seeds and juniper berries are added in addition.
We started with a more sophisticated recipe and enhanced it over the years.
for 80kg / 176 lb of cabbage we used
2400g / 5.3 lb onions
1200g / 2.6 lb horse radish
2.1 liters / 76 fl oz of white wine (we took 3 bottles of Riesling)
1500g / 53 oz of salt (1.5-2% of the cabbage weight) if possible, use kosher or non iodized salt
120g / 4.25 oz dried juniper berries
100g / 3.5 oz dried caraway seeds
80g / 2.8 oz dried yellow mustard seeds
30g / 1 oz dried garden dill / aneto
In addition, you can add freeze-dried lactic acid bacteria, to ensure a strong fermentation. We never did this and everything went well with the naturally present bacteria on the cabbage.