1. Selected heads of cabbage are core-shredded and soaked in tap water with 2.5% (by weight) salt concentration and allowed to ferment. During the initial stages of fermentation, there is a rapid evolution of gas caused by Leuconostoc mesenteroides; this process imparts much of the pleasant flavour to the product.
2.The next stage involves Lactobacillus cucumeris fermentation, resulting in an increase of lactic acid;
3. Finally after approximately 5 days at 20-24°C, the third stage, involving a further group of lactic acid bacteria such as Leuconostoc pentoaceticus, which yields more lactic acid combined with acetic acid, ethyl alcohol, carbon dioxide, and mannitol.
4. The fermentation process ends when the lactic acid production is approximately 1-2%. This can be tested by titration of the acid with a 0.1 N sodium hydroxide (NaOH) solution, using phenolphthalein (0.1% w/v) as colour indicator (i.e., 2-5 drops are added to the acid solution; colour will change from clear to pink and persists for 30 seconds). After the fermentation process, either the tank is sealed to exclude air or the product is then packed into glass jars or canned.
1. Select good, mature cabbages; remove external leaves; wash remaining heads well.
2. With a sharp knife cut the heads into four sections, removing the hearts. Slice two and a half kilos of cabbage into fine strips approximately 2 to 3 cm long.
3. Put above cabbage in pot or plastic container and mix well, adding two tablespoons of salt. Let stand for 15 minutes or more, while preparing another batch of cabbage. The quantity of salt added must be in accordance with the amount of cabbage used for proper fermentation. While the cabbage is in repose, the salt works to reduce the lot size, extract the juice, and soften the cabbage. This will prevent breakage of strips during packaging.
4. The cabbage is packed into clean wide-mouth 4 L glass or plastic jars.
5. Eliminate air bubbles from the cabbage by pressing hard with hand. This allows juices to penetrate the tissues and holes formed between strips. Soft pressing is recommended to avoid breaking the finer strips.
6. Place plastic bag full of water on top of the cabbage to prevent air from penetrating the container and the cabbage. Close the jars tightly. After approximately 24 hours of fermentation, the juices should have completely covered the cabbage. Otherwise, add a brine solution composed of 25 g of salt per L of water until all cabbage strips are covered. The presence of bubbles is an indication that fermentation is in progress. This process lasts from 5 to 6 weeks or until the bubbles disappear from the solution, after which the fermented cabbage is heated in a pot until boiling.
7. Pack cabbage into sterile jars and cover with hot juice, leaving a head space of 2.5 cm below the jar’s rim.
8. Place lids on each jar and sterilize the jars in a boiling water bath for 15 and 20 minutes for 0.5 L and 1 L jars, respectively.
an excerpt from handling and preservation of fruits and vegetables by combined methods for rural areas