Apr 25, 2018
This are valid for a transformation using low pH brine in a culture inoculated with a healthy variety of probiotic culture. Stage 1 takes 1 to 3 days. Multiple different aerobic bacteria start during the first 24 hrs, but shift to Leuconostoc mesenteroides therafter. Leuconostoc mesenteroides is one of the main producers of CO2 and CO2 production starts within 24 hours. CO2 forces oxygen out (and as Leuconostoc takes over, that bacterium metabolizes O2 to reduce it in your ferment). High CO2, low oxygen and increasing acidity inhibit yeast activity. Leuconostoc does NOT like temps above about 72, but other bacteria will take its place. Stage 2. High CO2 production. The ferment starts to fizz, because of the CO2. Sugars that are inherent in the vegetables are also being rapidly metabolized into CO2. Leuconostoc is Heterofermentative (meaning it produces various end products, such as different acids and dextrans) and takes over on day 2 through 5 and is generally finished by about day 5. Lactobacillus plantarum will start on about day 3 and increase thereafter. Lactic acid will be at about 1% by day 5 or 6. Kimchee is often packed at about day 3 to 5, while CO2 production is still high, but might be allowed to ferment further, while lids are on, tight. So Kimchee might also be fermented well past the CO2 production stage. Lids can be tightened on Kraut by day 5 or 6, but might still fizz slightly when opened. Stage 3 Days 6 through 14, is the period of the obligate anaerobes. CO2 production slows down and mostly stops. Lactobacilli, such as Lactobacillus plantarum take over and are predominant from day 6 to about day 20, getting gradually more acidic. Lactic acid will be at about 1.5 to 2% and will be in a ratio of about 4:1 with Acetic acid. pH 3.8 to 4.1. Here is where most European packers will stop and pack the kraut for sale. Lids can be tightened after about day 7 with no more fizzing. Stage 4 starts around 14 days to 20 days, when Lactobacillus brevis and other mixed aerobic and anaerobic but acid loving bacteria take over and gradually metabolize other remaining vegetable sugars until about day 30 to 45. By 6 weeks (45 days) all sugars are gone, including pentoses. Total acid increases to as much as 2.5% (still in a 4 to 1 ratio with acetic acid) and pH as low as 3.5. Sauerkraut may now be stored in a cupboard at room temperature, or in a refrigerator, for very prolonged periods, sometimes even up to several years.