The Species Involved
Four species of lactic acid bacteria have been associated with the fermentation of sauerkraut which is Leuconostoc mesenteroides, Pediococcus cerevisiae, Lactobacillus brevis and Lactobacillus plantarum. Lactobacillus mesenteroides is important in the initial stages (heterofermentative) of fermentation of sauerkraut (approximately 2.25% NaCl). However, P. cerevisiae is no longer recognized as a valid species name. This is because this Pediococcus species have been classified variously over the past 20 years and now the species mention is called Pediococcus pentosaceus. Therefore, P. pentosaceus will be used in reffering to pediococci present during sauerkraut fermentation.
Cabbage contains enough lactic acid bacteria to ferment by using salt alone. Cabbage should be contain up to 3.5% sugar. The sweeter the raw cabbage, the better the sauerkraut obtained. The bacteria strains must be ferment in a certain sequence to obtain a high quality if sauerkraut. In addition, the sauerkraut must be fermented around 65° F (18° C).
• Leuconostoc mesenteroides o Start fermentation first by producing around 0.25 to 0.3% of lactic acid. They are heterofermenters which means they produce different compounds such as lactic acid, acetic acid (vinegar), ethyl alcohol, carbon dioxide (soda gas) and mannitol. The last one is a bitter flavored compound which is metabolized later by Lactobacillus plantarum. If the temperature is raised above 72° F (22° C) they might not grow and that would be detrimental to the flavor of sauerkraut. In about 2 days Leuconostoc mesenteroides will produce 0.3% lactic acid and this increased acidity will restrict its growth.
• Lactobacillus plantarum o This strain takes over and continues fermenting until an acidity level of 1.5 to 2% is achieved. L. plantarum will ferment at temperatures higher than 72°