Although sauerkraut is often thought to be of German or Eastern European descent, this popular preserved cabbage and the process of vegetable fermentation itself are actually theorized to be of Chinese origin.
The Chinese fermented Chinese cabbage (also known as “napa cabbage”) with rice wine and the resulting sour cabbage was known as “suan cai” 酸菜 which literally translates into “sour vegetable”. The earliest known history of sauerkraut dates back 2,000 years ago, about the same time the Great Wall of China was being built; Chinese laborers consumed rice together with suan cai and various other pickled vegetables.
Genghis Khan introduced the fermented cabbage dish to Europe about a 1,000 years later. The Germans, called it “sauerkraut” (which literally translates into “sour cabbage” in German) and adapted the recipe to use locally available green cabbage (instead of Chinese cabbage), resulting in the sauerkraut popularly known today.
Prized by the ancient Romans for its taste and healthful properties, large quantites of the sour cabbage were carried by Roman troops in barrels during long journeys and were consumed in an effort to ward off intestinal infections.
Christopher Columbus nourished his sailors with sauerkraut to build their immunity against scurvy and other diseases.
The freshest possible green cabbage, good quality salt and the right quantity of salt are imperative to produce quality sauerkraut. Table salt and salt with any additives such as anti-caking agents are not recommended as they may affect the fermentation process. The quantity of salt should be mixed with the cabbage at a ratio of about 1.5% to 2.5% of the weight of cabbage. A ratio higher than that could stunt the fermentation process as the lactic-acid bacteria are unable to survive. One tablespoon of salt per two pounds of cabbage is a good rule of thumb.
Fresh cabbage heads are first shredded, mixed with salt and then squeezed by hand to release the juices in the cabbage which contain fermentable sugars and other nutrients that encourage microbial activity. The kneaded cabbage is then transferred to a crock, (traditionally stoneware fermentation crocks were used) and allowed to ferment undisturbed.
As the cabbage ferments, lactic acid-producing bacteria (LABs), primarily Lactobacilli, produce lactic acid along with other acids and a combination of gases (principally carbon dioxide). It is this acidity that serves as a preservative, helping to control the growth of harmful organisms which lead to food spoilage.
LABs thrive in anaerobic environments i.e., environments with no oxygen. For this reason, it is imperative to minimize oxygen exposure to the shredded cabbage; oxygen exposure affects the fermentation process and could result in the growth of harmful mold and yeast. Brine is an anaerobic environment, and ensuring the cabbage is submerged in brine at all times helps to avoid such undesirable outcomes. Do not stir the brine as this introduces oxygen.
Traditionally, water-sealed fermentation crocks were used to make sauerkraut and the water seal gives these crocks an advantage over modern day mason jars; the water seal prevents oxygen from entering the crock while allowing the carbon dioxide gases to bubble out.
Temperature control is a very important factor for a successful fermentation. The optimum temperature for sauerkraut fermentation is 18ºC – 21ºC (65ºF – 70ºF).
- 2 heads of fresh green cabbage
- Sea salt as required (usually 1.5% – 2.5% of the weight of cabbage)
Ensure all utensils and hands are thoroughly cleaned.
Remove the outer leaves of the cabbage heads. Reserve one or two outer leaves.
Cut the cabbage into quarters and remove the core.
Shred the cabbage into fine strips.
Sprinkle salt evenly over the shredded cabbage.
Using hands, squeeze and knead the shredded cabbage thoroughly to ensure the cabbage and the salt are well mixed and to draw out the juices. It is important to ensure that every single shred of cabbage is salted. Uneven salting of cabbage can be attacked by undesirable bacteria and organisms which could result in spoilage thereby rendering the entire batch unfit for consumption.
Continue squeezing and kneading until the cabbage turns limp and releases its juice.
Transfer the cabbage into a clean and dry crock. Press down as tightly as possible to encourage juice formation and remove any air bubbles.
Don’t fill the crock, leave some air space between the cabbage and the opening of the crock.
Pour the cabbage liquids. Ensure the cabbage is completely submerged in liquid. This step is absolutely critical. Lactobacillus cultures need an anaerobic environment to thrive and this brine is an anaerobic environment. If any of the cabbage is exposed to air, the fermentation process could be affected resulting in spoilage.
Take one or two of the outer leaves and cover the top of the shredded cabbage. Press down.
Place a stone weight on top of the cabbage. This prevents the shredded cabbage from floating up thereby ensuring the cabbage remains completely submerged in the brine at all times.
Both the cabbage and the stone weight should be immersed in the brine. This ensures that any scum or froth that forms on top of the brine does not reach the cabbage below the stone weights and could be easily skimmed off.
Cover the fermentation crock with the lid and seal it by filling the groove around the crock with water.
Set the crock aside undisturbed for at least 2 weeks to allow the fermentation process to take effect.
The sauerkraut is usually ready in 4-6 weeks, after which time it could be transferred to the fridge.
Refrigeration would not stop fermentation, but rather its slows down the process. Thus, the sauerkraut would continue to ferment and its ‘sourness’ will increase with time.
When spooning out sauerkraut from the crock, ideally, use a wooden spoon.